Schneider Electric 873RS Series Electrochemical Analyzers Instruction Sheet

Instruction
MI 611-168
January 2021
873RS Series
Electrochemical Analyzers
for Resistivity Measurements
Style C
Contents
Figures ........................................................................................................................................... 7
Tables ............................................................................................................................................ 9
1. Introduction ............................................................................................................................ 11
Quick Start ...............................................................................................................................11
Purpose ................................................................................................................................11
Checking Factory Configuration ..........................................................................................11
Verifying Valid Measurements ..............................................................................................11
Sensor Wiring.......................................................................................................................11
Sensor Calibration................................................................................................................13
Looking for More Information?............................................................................................13
General Description ..................................................................................................................13
Instrument Features ..................................................................................................................13
RoHS/WEEE Compliance Statement .......................................................................................15
Analyzer Identification ..............................................................................................................16
Standard Specifications..............................................................................................................17
Product Safety Specifications .....................................................................................................18
2. Installation .............................................................................................................................. 19
Mounting to a Panel – Plastic Enclosure 873RS-_ _ P..........................................................19
Mounting to a Panel – Metal Enclosure 873RS-_ _ W .........................................................19
Mounting to a Pipe (Metal Enclosure Only) 873RS-_ _ Y....................................................20
Mounting to a Surface, Movable Mount (Metal Enclosure Only) 873RS-_ _ Z....................21
Mounting to a Surface, Fixed Mount (Metal Enclosure Only) 873RS-_ _ X.........................23
Wiring of Plastic Enclosure .......................................................................................................24
Wiring of Metal Enclosure ........................................................................................................25
3. Operation ................................................................................................................................ 27
Overview...................................................................................................................................27
Display......................................................................................................................................27
Keypad......................................................................................................................................28
Operate Mode...........................................................................................................................29
Temp Key..................................................................................................................................29
View Setup Entries....................................................................................................................30
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MI 611-168 – January 2021
Contents
4. Configuration.......................................................................................................................... 31
Overview...................................................................................................................................31
Configure Mode........................................................................................................................31
Security Code............................................................................................................................31
Unlocking Analyzer Using Security Code ..................................................................................32
Locking Analyzer Using Security Code......................................................................................32
Configuration Setup Entries......................................................................................................32
CELL Display and Output Configuration (CELL)...............................................................33
Holding the Analog Output (Hold) .....................................................................................35
Compensation and Damping (Cd) .......................................................................................36
General Information Alarms.................................................................................................36
Setting Alarm Level(s) ..........................................................................................................37
H Alarm Configuration (HAC)............................................................................................38
Alarm Timers (HAtt, HAFt and HAdL) ...............................................................................39
L Alarm Configuration (LAC)..............................................................................................42
Alarm Timers (LAtt, LAFt, and LAdL).................................................................................43
User-Defined Upper Measurement Limit (UL) ....................................................................46
User-Defined Lower Measurement Limit (LL) .....................................................................46
User-Defined Upper Temperature Limit (UtL) .....................................................................47
User-Defined Lower Temperature Limit (LtL)......................................................................47
Scaling Analog Outputs........................................................................................................47
Output #1's 100% Analog Value (HO1) ..............................................................................48
Output #1's 0% Analog Value (LO1) ...................................................................................48
Output #2's 100% Analog Value (H02) ...............................................................................48
Output #2's 0% Analog Value (L02) ....................................................................................49
Basic Setup Entries ....................................................................................................................49
Unlocking Basic Setup Entries (bL) ......................................................................................50
Changing the Full Scale Range (FSC)...................................................................................50
Changing the Temperature Circuitry ....................................................................................51
Changing the Analog Output...............................................................................................57
Changing the Security Code (LCC) .....................................................................................62
5. Calibration .............................................................................................................................. 63
Electronic Bench Calibration ....................................................................................................63
Calibrating the Analyzer to a Specific Sensor .............................................................................69
Temperature Cell Factor (tCF1 and tCF2) and Cell Factor (CF1 and CF2) Adjustments .....69
Determining tCF..................................................................................................................70
Entering a tCF Value ............................................................................................................71
Determining (or Verifying) a CF ..........................................................................................71
Entering a CF Value .............................................................................................................73
4
Contents
MI 611-168 – January 2021
6. Diagnostics .............................................................................................................................. 75
Troubleshooting ........................................................................................................................75
Error Codes...............................................................................................................................75
Detachable Configuration Field Sheet ..................................................................................77
7. User Notes............................................................................................................................... 81
Single Sensor Use ......................................................................................................................81
Dual Sensor Use........................................................................................................................83
Redundant Sensor Operation ....................................................................................................84
Backup Sensor Operation..........................................................................................................85
8. Alarm Contact Maintenance.................................................................................................... 87
9. Warranty.................................................................................................................................. 89
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MI 611-168 – January 2021
6
Contents
Figures
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
Metal Enclosure Rear Panel Wiring. ....................................................................................12
Plastic Enclosure Rear Panel Wiring ....................................................................................12
Typical Front Panel Display and Keypad .............................................................................15
Data Label Location............................................................................................................16
Mounting to Panel - Plastic Enclosure.................................................................................19
Mounting to Panel - Metal Enclosure..................................................................................20
Metal Enclosure - Pipe Mounting........................................................................................21
Metal Enclosure - Movable Mount......................................................................................22
Metal Enclosure - Fixed Mount...........................................................................................23
Plastic Enclosure Rear Panel Wiring ....................................................................................24
Metal Enclosure Rear Panel Wiring .....................................................................................26
Display and Keypad ............................................................................................................28
Possible Alarm Wiring and Configuration Choices..............................................................37
ON/OFF Relationship between HAtt, HAFt and HAdL ....................................................41
Flow Diagram for Alarm Timer Logic .................................................................................42
ON/OFF Relationship between LAtt, LAFt, and LAdL ......................................................45
Flow Diagram for Alarm Timer Logic .................................................................................46
Jumpers for Temperature Compensation .............................................................................54
Thermistor Temperature Simulation (Metal Enclosure Shown) ...........................................55
RTD Temperature Simulation (Plastic Enclosure Shown)....................................................57
Jumpers for Changing Analog Output ................................................................................59
Output Terminals and Volt/Amm Meter (Plastic Enclosure Shown)....................................62
Temperature Simulation (NEMA 4X Enclosure Shown) .....................................................65
Bench Calibration (NEMA 4X Enclosure Shown)...............................................................67
Sensor Identification ...........................................................................................................70
Alarm Contact Reconditioning Circuit ...............................................................................87
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MI 611-168 – January 2021
8
Figures
Tables
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
Product Safety Specifications ...............................................................................................18
Recommended Conduit and Fitting (Due to Internal Size Restraints) .................................26
Key Functions .....................................................................................................................28
Configuration Setup Entries................................................................................................32
CELL Code - Display and Output Configuration ...............................................................35
Hold Code - Hold Analog Output and Alarms ...................................................................36
Cd Code - Compensation and Damping.............................................................................36
HAC Code - High Alarm Configuration.............................................................................39
HAtt, HAFt, and HAdL Time Codes..................................................................................40
LAC Code - Low Alarm Configuration ...............................................................................43
LAtt, LAFt, and LAdL Time Codes.....................................................................................44
Basic Setup Entry Selection .................................................................................................49
Jumper Positions for Temperature Transducer......................................................................52
Jumper Position for the Various Analog Outputs.................................................................58
Troubleshooting Symptoms.................................................................................................75
Error/Alarm Messages .........................................................................................................75
Configuration Setup Entries................................................................................................77
Hold Code—Hold Analog Output Values ..........................................................................77
Basic Setup Entry Selection .................................................................................................77
CELL Code—Display and Output Configuration ..............................................................78
Cd Code—Compensation and Damping ............................................................................78
HAC and LAC Codes—Alarm Configuration ....................................................................79
HAFt, HAdL, LAFt, and LAdL Time Codes .......................................................................79
Troubleshooting Symptoms.................................................................................................79
Error/Alarm Messages .........................................................................................................79
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MI 611-168 – January 2021
10
Tables
1. Introduction
Quick Start
Purpose
The purpose of this section is to:
♦ Help you to wire your analyzer.
♦ Familiarize you with the analyzer configuration as received from the factory.
♦ Assist you in verifying that your analyzer is in calibration.
♦ Explain normal operation.
Checking Factory Configuration
Refer to analyzer label and Configuration setup entries in Table 4 on page 32 and Table 12 on
page 49. There is space provided to make any notations you wish in the last column of each table.
Verifying Valid Measurements
Your analyzer was calibrated at the factory. Therefore, you should not have to calibrate it.
However, if you wish to check the calibration, install resistors from the resistor kit included and
follow procedures from “Electronic Bench Calibration” on page 63, with the analyzer LOCKED.
Sensor Wiring
Wiring installation must comply with any existing local regulations
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MI 611-168 – January 2021
1. Introduction
Figure 1. Metal Enclosure Rear Panel Wiring.
POWER
OUTPUT 1
OUTPUT 2
CLEAR
WHT
RED
GRN
SENSOR 2
RED
WHT
CLEAR
GRN
SENSOR 1
1 2 3 3A 4 5 6 7
2- 2+ 1- 1+
TB2
TB4
TB1
TB3
L2 L1
NC C NO NC C NO
LO
HI
L ALM
H ALM
To Earth Ground Connection
Figure 2. Plastic Enclosure Rear Panel Wiring
TB2
GREEN
RESISTIVITY SIGNAL
FROM 871CC SENSOR
SENSOR 1
WHITE
TEMPERATURE SIGNAL
FROM 871CC SENSOR
TEMPERATURE SIGNAL
FROM SECOND
871CC SENSOR
SENSOR 2
RED
RESISTIVITY SIGNAL
FROM SECOND
871CC SENSOR
CLEAR
CLEAR
1
2
3A
4
WHITE
5
RED
6
GREEN
TB3
3
7
TB1
G L2/N L1
POWER
12
M
+
M
1
N
O
7
C
1
N
C
2
N
O
2
C
2
N
C
MEASUREMENT
OUTPUT
H ALM
L ALM
1. Introduction
MI 611-168 – January 2021
Sensor Calibration
871CC “resistivity” sensors are manufactured to be ±2% accurate of their nominal 0.1 cm-1 cell
value. These sensors are also tested and labeled with their individual cell factors (CF) as well as the
true temperature at which a thermistor is exactly 100 kΩ or RTD is 100 Ω. The overall system
accuracy may be improved by entering the individual sensor parameters into the analyzer.
“Entering a tCF Value” on page 71 and “Entering a CF Value” on page 73 are the pertinent
procedures to follow to calibrate the 873RS analyzer for the individual sensor being used.
Looking for More Information?
For more detailed information, refer to the following sections of this manual:
For installation information, refer to “Installation” on page 19. For dimensional information,
refer to DP 611-163.
For detailed explanation of the controls and indicators, refer to “Operation” on page 27.
For detailed configuration instructions, refer to “Configuration” on page 31.
For detailed calibration instructions, refer to “Calibration” on page 63.
If you need additional help, please call the Electrochemical Service Center at 1-508-549-4730 in
the U.S.A. or call your local Invensys representative.
General Description
The 873RS Resistivity Analyzer interprets the resistivity of aqueous solutions. Its measurement
display may be read in either megohm-cm (MΩ •cm), or percent (%). Solution temperature is also
measured by the 873RS for automatic temperature compensation and may be displayed whenever
the user wants.
It provides an isolated output signal proportional to the measurement for transmission to an
external receiver. The general purpose panel-mounted analyzer transmits one output signal; the
field-mounted (NEMA 4X enclosure) analyzers transmits two output signals.
Instrument Features
Described below are some of the features of the 873RS Electrochemical Analyzer:
♦ Plastic or Metal Enclosure
♦ Dual Sensor Input
♦ Dual Alarms
♦ Dual Analog Outputs on Metal Enclosure
♦ EEPROM Memory
♦ Instrument Security Code
♦ Hazardous Area Classification, Metal Enclosure only
♦ Front Panel Display
♦ Front Panel Keypad
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MI 611-168 – January 2021
1. Introduction
♦ Application Flexibility
♦ Storm Door Option
Enclosures
The plastic enclosure is intended for panel mounting in general purpose locations, and mounts in
a 1/4 DIN size panel cutout. It meets the enclosure ratings of NEMA 1, CSA Enclosure 1, and
IEC Degree of Protection IP-45.
The metal enclosure is intended for field locations and may be panel, pipe, or surface mounted.
The housing is extruded aluminum coated with a tough epoxy-based paint. The enclosure is
watertight, dusttight, corrosion-resistant, meeting the enclosure ratings of NEMA 4X, CSA
Enclosure 4X, and IEC Degree of Protection IP-65, and fits in a 92 x 92 mm (3.6 x 3.6 in) panel
cutout (1/4 DIN size). The metal enclosure provides protection against radio frequency
interference (RFI) and electromagnetic interference (EMI).
Dual Alarms
Two independent, nonpowered Form C contacts, rated 5 A noninductive, 125 V ac/30 V dc
(minimum current rating 1 A). Inductive loads can be driven with external surge-absorbing
devices installed across contact terminations.
! CAUTION
When the contacts are used at signal levels of less than 20 W, contact function may
become unreliable over time due to the formation of an oxide layer on the contacts.
See “Alarm Contact Maintenance” on page 87.
No Battery Backup Required
Non-volatile EEPROM memory is employed to protect all operating parameters and calibration
data in the event of power interruptions.
Instrument Security Code
A combination code lock method, user configurable, provides protection of operational
parameters from accidental or unauthorized access.
Front Panel Display
The instrument's display consists of a four-digit bank of red LEDs with decimal point, and an
illuminated legend area to the right of the LEDs (see Figure 3). The 14.2 mm (0.56 in) display
height provides visibility at a distance up to 6 m (20 ft) through a protective window on the front
panel.
The measurement value is the normally displayed data. If other data is displayed because of prior
keypad operations, the display automatically defaults to the measurement value 10 seconds (called
timing out) after the last keypad depression.
If no fault or alarm conditions are detected in the instrument, the measurement value is steadily
displayed. If fault or alarm conditions are detected, the display alternately displays, at a 1 second
rate, the measurement value and a fault or alarm message.
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1. Introduction
MI 611-168 – January 2021
Front Panel Keypad
The instrument front panel keypad consists of eight keys. Certain keys are for fixed functions;
other keys are for split functions. The upper function of a split function key is actuated by
pressing the shift key in conjunction with the split function key. Refer to Figure 3.
Application Flexibility
The 873 Analyzer offers application flexibility through its standard software package. The
software, run on the internal microprocessor, allows the user to define and set operating
parameters particular to his application. These parameters fall into four general categories:
Measurement Range, Alarm Configuration, Diagnostics, and Output Characterization. These
parameters are retained in the EEPROM nonvolatile memory. Following power interruptions, all
operating parameters are maintained.
Storm Door Option
This door is attached to the top front surface of the enclosure. It is used to prevent accidental or
inadvertent actuation of front panel controls, particularly in field mounting applications. The
transparent door allows viewing of the display and is hinged for easy access to the front panel
controls.
Figure 3. Typical Front Panel Display and Keypad
ANALYZER MODEL
MEASUREMENT VALUE
DISPLAY (4-DIGITS PLUS
DECIMAL POINT)
DUAL FUNCTION KEY (FOR
LOWER FUNCTION, PRESS
KEY ONLY.
FOR TOP FUNCTION,
PRESS/HOLD SHIFT
AND KEY)
ANALYZER TYPE
873
MEASUREMENT
LEGEND UNITS
DISPLAY
Resistivity Analyzer
8.8.8.8.
Phase
Cal Hi
Alt Cel
Temp
H Alm
Next
Cal Lo
Setup
L Alm
Lock
Shift
MΩ • %
cm
Cel
Abso
SINGLE FUNCTION KEY
(PRESS KEY ONLY)
Enter
RoHS/WEEE Compliance Statement
This product is exempt from the European Directive 2002/95/EC on the restriction of the use of
certain hazardous substances in electrical and electronic equipment (RoHS), as provided by
Article 2 of that Directive in conjunction with the Product Category #9: “Monitoring and
Control Instruments.”
This product complies with the European Directive 2002/96/EC on Waste Electrical and
Electronic Equipment (WEEE) and is marked accordingly. At end of product life users should
contact Global Customer Support for return authorization and shipment instructions.
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MI 611-168 – January 2021
1. Introduction
Analyzer Identification
A data label is fastened to the side surface of the enclosure. This dataplate provides Model
Number and other information pertinent to the particular analyzer purchased. Refer to Figure 4.
Figure 4. Data Label Location
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1. Introduction
MI 611-168 – January 2021
Standard Specifications
Supply Voltages
–A
–B
–C
–E
–J
120 V ac
220 V ac
240 V ac
24 V ac
100 V ac
Supply Frequency
50 or 60 Hz, ±3 Hz
Output Signal
I
T
E
Ambient Temperature
Limits
–25 to +55°C (–13 to +131°F)
Measurement Ranges
0 to 2.000 MΩ•cm (minimum)
0 to 5.000 MΩ•cm
0 to 10.00 MΩ•cm
0 to 15.00 MΩ•cm
0 to 20.00 MΩ•cm (maximum)
4-20 mA isolated
0-10 V dc isolated
0-20 mA isolated
Temperature Measurement Range
–17 to +150°C (0 to 302°F)
Temperature
Compensation Range
0 to 120°C (32 to 248°F)
Relative Humidity Limits
5 to 95%, noncondensing
Accuracy of Analyzer
±0.5% of FSC range utilized at 25°C
Analyzer Identification
Refer to Figure 4.
Dimensions
Plastic Enclosure 92(H) x 92(W) x 183(L) mm, 3.6 x 3.6 x 7.6 in
Metal Enclosure 92(H) x 92(W) x 259(L) mm, 3.6 x 3.6 x 10.1 in
Enclosure/Mounting Options
–P
–W
–X
–Y
–Z
Approximate Mass
Plastic Enclosure 0.68 kg (1.5 lb)
Metal Enclosure (NEMA 4X) (with Brackets)
Panel Mounting 1.54 kg (3.4 lb)
Pipe Mounting 2.31 kg (5.1 lb)
Fixed Surface Mounting 2.22 kg (4.9 lb)
Movable Surface Mounting 3.13 kg (6.9 lb)
Instrument Response
Three second response for 90% change when used for single sensor
measurement (when zero measurement damping is selected in Configuration
Code). Temperature response is 15 seconds maximum. Seven second response
for 90% change when used for dual sensor measurement.
Measurement Damping
Choice of 0, 10, 20, 40, 80, or 160 second, additional damping configurable from
keypad. Damping affects displayed parameters and analog outputs.
Alarms
Plastic (Noryl) Panel Mount
Metal Panel Mount
Metal Surface Mount
Metal Pipe Mount
Metal Movable Surface Mount
Two alarms configurable via keypad
Individual set points continuously adjustable 0 to full scale via keypad
Hysteresis selection for both alarms; 0 to 99% of full scale value,
configurable via keypad
Three timers for both alarms, adjustable 0 to 99 minutes, configurable via
keypad. Allows for trigger timing and on/off control with delay. Timers can be
set to allow chemical feed, then delay for chemical concentration control.
Alarm Contacts
Two independent, nonpowered Form C contacts. Rated 5 A noninductive, 125 V
ac/30 V dc (minimum current rating 1 A). Inductive loads can be driven with
external surge-absorbing devices installed across contact terminations.
CAUTION: When the contacts are used at signal levels of less than 20 W,
contact function may become unreliable over time due to the formation of an
oxide layer on the contacts. See “Alarm Contact Maintenance” on page 87.
Alarm Indication
Alarm status alternately displayed with measurement on LED display
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MI 611-168 – January 2021
1. Introduction
Analog Output (dual outputs on
metal units)
Isolated, powered outputs
0-10 V (minimum load 1 kΩ)
0-20 mA (800Ω maximum loop resistance)
4-20 mA (800Ω maximum loop resistance)
RFI Susceptibility (when all sensor
and power cables are enclosed in a
grounded conduit)
Plastic Enclosure: <0.5 V/m from 27 to 1000 MHz
Metal Enclosure: >10 V/m from 27 to 1000 MHz
Electromagnetic Compatibility (EMC) The Model 873RS Electrochemical Analyzer, 220 V ac or 240 V ac systems with
metal enclosure, comply with the requirements of the European EMC Directive
89/336/EEC when the sensor cable, power cable, and I/O cables are enclosed in
rigid metal conduit. See Table 2 on page 26.
The plastic case units are intended for mounting in metal consoles or cabinets.
The plastic case units will comply with the European EMC Directive 89/336/EEC
when mounted in a metal enclosure and the I/O cables extending outside the
enclosure are enclosed in metal conduit. See Table 2 on page 26.
Product Safety Specifications
Table 1. Product Safety Specifications
Testing Laboratory, Types of Protection, and
Area Classification
Application Conditions
FM for use in general purpose (ordinary) locations.
FM nonincendive for use in Class I, II, Division 2,
groups A, B, C, D, F, and G, hazardous locations.
Electrical Safety
Design Code
FGZ
For instruments with metal enclosure only.
Temperature Class T6.
FNZ
CSA (Canada) suitable for use in Class I, Division For instruments with metal enclosure only. CNZ
2, Groups A, B, C, and D; hazardous locations.
24 V, 100 V, and 120 V ac (Supply Option -A,
-E, -J) only.
Temperature Class T6.
NOTE
The Analyzer has been designed to meet the electrical safety descriptions listed in the
table above. For detailed information or status of testing laboratory
approvals/certifications, contact your Global Customer Support representative.
! CAUTION
1. When replacing covers on the 873 metal case, use Loctite (Part No. S0106ML) on
the threads for the front cover and Lubriplate (Part No. X0114AT) on the threads for
the rear cover. Do not mix.
2. Exposure to some chemicals may degrade the sealing properties of Polybutylene
Teraethalate and Epoxy Schneider Legacy Relay 276XAXH-24 used in relays K1 and
K3. These materials are sensitive to acetone, MEK, and acids. Periodically inspect
relays K1 and K3 for any degradation of properties and replace if degradation is
found.
18
2. Installation
! CAUTION
Under certain operating conditions, a static charge can build up in the measurement
piping and dissipate through the sensor, damaging electrical components. This has
happened when using plastic piping, high flow rates, and very clean water. As a
countermeasure, placing a “dummy sensor” or other metal object connected to
ground just prior to the measurement sensor helps to dissipate the charge, thus
preventing ESD damage to analytical instrumentation. Please contact Global
Customer Support for additional information on this issue.
Mounting to a Panel – Plastic Enclosure 873RS-_ _ P
The plastic enclosure is mounted to a panel as described below (see Figure 5).
1. Size panel opening in accordance with dimensions specified on DP 611-162.
2. Insert spring clips on each side of Analyzer.
3. Insert Analyzer in panel opening until side spring clips engage on panel.
4. From rear of panel (and Analyzer), attach and tighten the top and bottom mounting
screws until analyzer is securely held in place.
Figure 5. Mounting to Panel - Plastic Enclosure
MOUNTING SCREW
SPRING CLIPS (2)
Mounting to a Panel – Metal Enclosure 873RS-_ _ W
The metal enclosure can also be mounted to a panel as follows.
1. Make cutout in panel in accordance with DP 611-162.
2. Insert Analyzer through panel cutout and temporarily hold in place. (Rear bezel will
have to be removed for this procedure.)
3. From rear of panel, slide plastic clamp onto enclosure until clamp latches (two) snap
into two opposing slots on longitudinal edges of enclosure. See Figure 6.
4. Tighten screws (CW) on clamp latches until enclosure is secured to panel.
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MI 611-168 – January 2021
2. Installation
5. Reassemble rear bezel to enclosure using four screws.
Figure 6. Mounting to Panel - Metal Enclosure
REMOVABLE REAR BEZEL
CLAMP LATCH (2)
PANEL THICKNESS NOT
TO EXCEED 20 MM (0.8 IN)
PLASTIC CLAMP
PLASTIC CLAMP
SLOTS IN
LONGITUDINAL
EDGES OF
ENCLOSURE
CLAMP LATCH SCREW (2)
CLAMP LATCH (2)
Mounting to a Pipe (Metal Enclosure Only) 873RS-_ _ Y
1. Locate horizontal or vertical DN 50 or 2 inch pipe.
2. Assemble universal mounting as follows:
a. Place hex bolts (5) through spacer (3) into support bracket (2).
b. Slide nylon washers (11) over bolts (5).
c. Slide bolts through pipe mounting bracket (1) and fasten assembly tightly with
hardware designated 7, 6, and 13.
d. Attach pipe mounting bracket (1) to pipe using U-bolts (12) and hardware
designated 6 and 13.
3. Slide Analyzer into support bracket and slide strap clamp (4) onto Analyzer. Using
two screws, nuts, and washers, attach strap clamp to support bracket to secure
Analyzer.
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2. Installation
MI 611-168 – January 2021
Figure 7. Metal Enclosure - Pipe Mounting
SUPPORT
BRACKET
MOUNTING
BRACKET
SPACER
U-CLAMP
STRAP
CLAMP
MOUNTING
BRACKET
0.312-18 NUTS (4)
VERTICAL
DN50 OR
2-IN. PIPE
0.190-32 SCREWS (2
U-CLAMP
NOMINAL DN50 OR 2-IN.
PIPE. HORIZONTAL PIPE
SHOWN. TWO U-CLAMPS
ARE USED TO SECURE
BRACKET TO PIPE.
PIVOT BOLT; MOUNTED
ENCLOSURE CAN BE
ROTATED UP TO 60°
IN VERTICAL PLANE.
STRAP
CLAMP
Mounting to a Surface, Movable Mount
(Metal Enclosure Only) 873RS-_ _ Z
1. Locate surface on which you wish to mount the Analyzer.
2. Referring to Figure 8, use wall bracket (12) as template for drilling four holes into
mounting surface. Notice that the holes in the wall bracket are 9.53 mm (0.375 in) in
diameter.
3. Attach wall bracket (12) to surface using four bolts, washers, and nuts.
4. Assemble universal mounting as follows:
a. Place hex bolts (5) through spacer (3) into support bracket (2).
b. Slide nylon washers (11) over bolts (5).
c. Slide bolts through universal mounting bracket (1) and fasten assembly finger
tight with hardware designated 9, 10, and 16.
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MI 611-168 – January 2021
2. Installation
5. Slide Analyzer into support bracket and slide strap clamp (4) onto Analyzer. Using
two screws, nuts, and washers, attach strap clamp to support bracket to secure
Analyzer.
6. Lift entire assembly of Step 5, align mounting bracket and wall bracket pivot bolt
holes, and then insert pivot bolt (13) through wall and mounting bracket into nylon
washers and locking nut.
7. Rotate bracket and Analyzer assembly in horizontal plane to desired position and lock
in place using screw and washer.
Figure 8. Metal Enclosure - Movable Mount
WALL BRACKET
PIVOT BOLT
(0.250 2 20) FOR
HORIZONTAL
PLANE ROTATION
SUPPORT
BRACKET
STRAP CLAMP
4 BOLTS
SUPPLIED
BY USER
PIVOT BOLT
().312-18) FOR
VERTICAL PLANE
ROTATION
NYLON WASHER
AND LOCK NUT
22
LOCK MOUNTING BRACKET IN PLACE
USING 0.190-32 SCREW AND WASHER
PIVOT
BOLT
SUPPORT
BRACKET
MOUNTING
BRACKET
STRAP
CLAMP
0.190-32 SCREWS (2)
2. Installation
MI 611-168 – January 2021
Mounting to a Surface, Fixed Mount
(Metal Enclosure Only) 873RS-_ _ X
1. Locate mounting surface for Analyzer.
2. Referring to Figure 9, use mounting bracket (1) as template for drilling four holes into
mounting surface. Notice that holes in mounting bracket are 8.74 mm (0.344 in) in
diameter. Do not attach mounting bracket to surface at this time.
3. Assemble universal mounting as follows:
a. Place hex bolts (5) through spacer (3) into support bracket (2).
b. Slide nylon washers (11) over bolts (5).
c. Slide bolts through universal mounting bracket (1) and fasten assembly together
with hardware designated 7, 6, and 12.
d. Attach universal mounting bracket (1) to wall.
4. Slide Analyzer into support bracket and slide strap clamp (4) onto Analyzer. Using
two screws, nuts, and washers, attach strap clamp to support bracket to secure
Analyzer.
Figure 9. Metal Enclosure - Fixed Mount
SURFACE (REFERENCE)
SPACER
SUPPORT
BRACKET
MOUNTING
STRAP BRACKET
CLAMP
PIVOT BOLT: MOUNTED
ENCLOSURE CAN BE
ROTATED UP TO 60°
IN VERTICAL PLANE
STRAP
CLAMP
0.190-32 SCREWS (2)
23
MI 611-168 – January 2021
2. Installation
Wiring of Plastic Enclosure
1. Remove optional rear cover assembly BS805QK, if present.
2. Connect H and L alarm wires to TB3 as shown in Figure 10. Failsafe operation
requires connections be made between NC and C and the alarms be configured active.
Refer to “General Information Alarms” on page 36.
3. Connect wires from external circuit for Analyzer measurement output to terminals
TB3–1(+) and TB3–2(–). Refer to Figure 10.
NOTE
1. Only sensors with 0.1 cm-1 cell factor should be used with the 873RS Analyzer.
Models 500, 900, 910, 920, 921, and 923 Series should not be used with the 873
Analyzer. 871CC Sensors A2 through F2 use a 100 k Ω thermistor for temperature
compensation. Sensors K2 through M2 use a Pt 100 RTD for temperature
compensation and are recommended for all measurements at elevated temperature.
2. If sensors are to be used in a solution with a high applied voltage, the outer
electrode of each sensor (green wire Terminals 1 and 7) must be connected to earth
ground.
3. Wiring installations must comply with any existing local regulations.
4. Remove factory-installed jumper assembly from terminal block TB2 and discard.
5. Connect sensor wires to Analyzer terminal block (TB2) in accordance with Figure 10.
If a single sensor is used with this Analyzer, it may be wired to either sensor input. See
“CELL Display and Output Configuration (CELL)” on page 33, “H Alarm
Configuration (HAC)” on page 38, and “L Alarm Configuration (LAC)” on page 42.
6. Connect power wires to terminal block TB1 as shown in Figure 10.
7. Attach optional rear panel cover, if present.
Figure 10. Plastic Enclosure Rear Panel Wiring
TB2
GREEN
RESISTIVITY SIGNAL
FROM 871CC SENSOR
SENSOR 1
WHITE
TEMPERATURE SIGNAL
FROM 871CC SENSOR
TEMPERATURE SIGNAL
FROM SECOND
871CC SENSOR
SENSOR 2
RED
RESISTIVITY SIGNAL
FROM SECOND
871CC SENSOR
CLEAR
CLEAR
1
2
3A
4
WHITE
5
RED
6
GREEN
TB3
3
7
TB1
G L2/N L1
POWER
24
M
+
M
1
N
O
7
C
1
N
C
2
N
O
2
C
2
N
C
MEASUREMENT
OUTPUT
H ALM
L ALM
2. Installation
MI 611-168 – January 2021
Wiring of Metal Enclosure
NOTE
1. Wiring installations must comply with any existing local regulations.
2. To maintain enclosure tightness such as NEMA 4X, CSA Enclosure 4X, or IEC
Degree of Protection IP-65, wiring methods and fittings appropriate to the ratings
must be used. See Table 2 on page 26. Alarm wires should run through the same
conduit as the power wires. Sensor wires and analog output wires should be run
through separate conduit openings.
1. Remove back cover to access terminal/power board.
2. Connect H and L Alarm wires to TB3 as shown in Figure 11. Failsafe operation
requires connections to be made between contacts NO and C, and the alarms to
configured active. Refer also to “General Information Alarms” on page 36.
3. Connect wires from external circuits for Analyzer temperature or measurement
outputs to terminal TB4.
NOTE
1. Only sensors with a 0.1 cm-1 cell factor should be used with the 873RS Analyzer.
Models 500, 900, 910, 920, 921, and 923 Series should not be used with the 873
Analyzer. 871CC Sensors A2 through F2 use a 100 kΩ thermistor for temperature
compensation. Sensors K2 through M2 use a Pt 100 RTD for temperature
compensation and are recommended for all measurements at elevated temperature.
2. If the sensors are to be used in a solution with a high applied voltage, the outer
electrode from each sensor (green wire terminals 1 and 7) must be connected to
earth ground.
4. Connect sensor wires to Analyzer terminal block TB2 as shown in Figure 11. If a
single sensor is used with this Analyzer, it may be wired to either sensor input but
must be configured properly. See “CELL Display and Output Configuration (CELL)”
on page 33, “H Alarm Configuration (HAC)” on page 38, and “L Alarm
Configuration (LAC)” on page 42.
5. Connect power wires to terminal block 1 as indicated in Figure 11. The earth
(ground) connection from the power cord should be connected to the stud located in
the bottom of the case. The stud grounds the instrument and is mandatory for safe
operation.
25
MI 611-168 – January 2021
2. Installation
Figure 11. Metal Enclosure Rear Panel Wiring
POWER
OUTPUT 1
OUTPUT 2
CLEAR
WHT
RED
GRN
SENSOR 2
RED
WHT
CLEAR
GRN
SENSOR 1
1 2 3 3A 4 5 6 7
2- 2+ 1- 1+
TB2
TB4
TB1
TB3
L2 L1
NC C NO NC C NO
LO
HI
L ALM
H ALM
EARTH GROUND
Table 2. Recommended Conduit and Fitting (Due to Internal Size Restraints)
Conduit
Fitting
Rigid Metal
1/2-inch Electrical Trade Size
T&B (a) /#370
Semi-rigid Plastic
T&B #LTC 050
T&B #LT 50P or T&B #5362
Semi-rigid Plastic, Metal Core
Anaconda Type HC, 1/2-inch
T&B #LT 50P or T&B #5362
Flexible Plastic
T&B #EFC 050
T&B #LT 50P or T&B #5362
a. Thomas & Betts Corp., 1001 Frontier Road, Bridgewater, NJ 08807-0993
NOTE
1. The cover screws are self-tapping and have a limited number of taps. Do not
repeatedly remove and tighten these screws.
2. When replacing covers on the 873 metal case, use Loctite (Part No. S0106ML) on
the threads for the front cover and Lubriplate (Part No. X0114AT) on the threads
for the rear cover. Do not mix.
3. It is recommended that sensor and interconnect cable be run in 1/2 inch conduit
for protection against moisture and mechanical damage. Do not run power and
control wiring in the same conduit.
26
3. Operation
Overview
The 873 functions in two modes, OPERATE and CONFIGURE.
In the OPERATE Mode, the 873 automatically displays its measurement and outputs a
proportional analog signal. Also, while in the OPERATE Mode, a user may read all the parameter
settings and the solution temperature.
In the CONFIGURE Mode, the user may change any of the parameters previously entered. All
873 Analyzers are shipped configured, either with factory default settings or user defined
parameters, as specified.
Utilizing either mode requires understanding the functions of both the keypad and display.
Display
The display, Figure 12, is presented in two parts, a measurement/settings display and a backlit
engineering units/cell 2 display. There are four possible automatic measurement displays as
follows:
♦ The measurement of Cell 1, expressed in MΩ•m.
♦ The measurement of Cell 2, expressed in MΩ•cm.
♦ The ratio between Cell 1 and Cell 2, expressed in %:
Cell 1
--------------- × 100 = Percent
Cell 2
Example:
Cell 1 is measuring 10.0 MΩ •cm water. Cell 2 is measuring 17.1 MΩ •cm water. Ratio would
read 58.5%.
♦ The % rejection between Cell 1 and Cell 2, expressed in % is:
Cell 1
1 – --------------- × 100 = Percent
Cell 2
Example:
Cell 1 is measuring 10.0 MΩ •cm water. Cell 2 is measuring 17.1 MΩ •cm water. Percent rejection
would read 41.5%.
To read anything other than the measurement or to make a configuration or calibration change
requires keypad manipulations.
27
MI 611-168 – January 2021
3. Operation
Keypad
The keypad, Figure 12, is made up of eight keys, six of which are dual function. The white
lettered keys represent normal functions while the blue lettered keys represent the alternate
function. To operate the white lettered keys, just push them. To operate the blue lettered keys,
press/hold Shift and then press the key. The functions of all keys are presented in Table 3.
Figure 12. Display and Keypad
ANALYZER TYPE
DISPLAY
873
ResistivityAnalyzer
8.8.8.8.
KEYPAD
Phase
Cal Hi
Alt Cel
Temp
H Alm
Next
Cal Lo
Setup
L Alm
Lock
Shift
MΩ •
cm
Cel
2
%
ENGINEERING UNITS
ARE BACKLIT. ONLY
THE ONE CONFIGURED
IS VISIBLE.
Abso
Enter
Table 3. Key Functions
Shift
Abso
Phase
Temp
Shift: Push and hold actuates the blue upper-function keys. Holding the Shift key while performing any
function overrides the 10 second time-out allowing longer viewing of a value or code for as long as the
key is held.
Abso: Push this key to display the absolute resistivity value of cell, no temperature compensation.
Pushing this key in Ratio or % Rejection displays absolute resistivity of Cell 1.
Increment: Push to increase the value of the flickering number appearing on display. Each push causes
the value to increase by one. Holding the key increases the count at approximately one per second.
When 9 or the highest number in the configuration sequence is reached, display goes to 0.
Phase: This key is used during bench calibration only to implement a phase calibration. Phase
calibration provides calibration of the quadrature measurement circuitry. This accurately allows
compensation of the resistivity measure for cable and sensor capacitance.
Temp: Push and view the process medium temperature. This may be the actual temperature or a
manually set value, as configured. The temperature is displayed with one decimal point which alternates
with °C or °F as chosen.
Enter: Is used to display the value or code of a setup entry. It is also used to select a parameter or code
by entering the value or code into the memory.
Enter
28
3. Operation
MI 611-168 – January 2021
Table 3. Key Functions (Continued)
Alt Cel
Next
Setup
Alt Cell: If the display reads the resistivity of Cell 1, push Alt Cel to display Cell 2. If the display reads Cel
2, push Alt Cel to display the resistivity of Cell 1. Pushing this key when in % Rejection or Ratio displays
the value of Cell 1.
Next: Used to select one of the four display digits similar to a cursor except that it causes the digit to
flicker. Also used to select the next entry choice of the setup function.
Setup: Used to select and access analyzer configuration parameters and values.
Lock: Used to display the lock status and lock or unlock the analyzer.
Lock
Cal Lo
L Alm
Cal Hi
H Alm
Cal Lo: Used to set the lower calibration level (0 MΩ⋅cm) during bench calibration.
L Alarm: Used to display and set the set point value for the relay associated with this alarm when
configured as a measurement alarm.
Cal Hi: Used to set the desired upper calibration level during bench calibration.
H Alarm: Used to display and set the set point level for the relay associated with this alarm when
configured as a measurement alarm.
NOTE
1. Pressing NEXT and Δ simultaneously allows the user to step backward through the
Setup program or digit place movement. One cannot reverse number count by this
procedure.
2. Pushing SHIFT and ENTER simultaneously circumvents the 10-second wait
between Setup entries.
Operate Mode
As soon as the 873 Resistivity Analyzer is powered, it is in the Operate Mode. The instrument
first conducts a self diagnostic test, momentarily displays the firmware version, and then
automatically displays the measurement.
While in the Operate Mode, the user may view the measurement, view the temperature, and view
all the parameter settings configured in the Configuration Setup Entries and Basic Setup Entries.
Temp Key
To view the process temperature, execute the following procedure:
Starting in the measurement mode, push Temp. The display then changes from the resistivity
measurement to the process medium temperature or manually adjusted temperature.
If dual sensors are used, press/hold Next and press Temp to display the process medium
temperature or manually adjusted temperature of Cel 2. The Cel 2 legend will be illuminated.
Using this procedure, you can display the temperature but cannot change it.
The display is a rounded whole number with the temperature units (C or F) alternating with
tenths of degrees. Once the unit is unlocked (see “Unlocking Analyzer Using Security Code” on
page 32), the Temp key, used in conjunction with the increment (Δ) key, allows the temperature to
29
MI 611-168 – January 2021
3. Operation
be changed from °C to °F or vice versa, as well as allowing the use of manual temperature
compensation at a given temperature (decimal shown after temperature). When Temp is pushed,
the process temperature is displayed on the readout. Pushing Δ repeatedly causes the display to
sequence from the displayed value through the following sequence example:
(1) 77.F
(2) 77.F.
(3) 25.C
(4) 25.C.
or
or
or
or
77.0
77.0
25.0
25.0.
When the decimal point appears after the C or F, the process temperature is compensated
manually at the temperature displayed. To change that temperature, use Next and Δ to display the
new value; then push Enter. Automatic temperature compensation, however, cannot be changed
by this procedure. See “Calibrating the Analyzer to a Specific Sensor” on page 69. To return to
automatic compensation, sequence the display to remove the decimal point after C or F. Then
press Enter.
View Setup Entries
Setup Entries may be reviewed at any time.
To view any of the Setup Entries, follow the procedures given in the “Configuration Setup
Entries” on page 32 or “Basic Setup Entries” on page 49, but do not “Unlock” the instrument.
When viewing the Setup Entries, you may page through the parameters as rapidly as you wish
(Shift + Setup, Next one or more times). However, once Enter is pushed (Enter must be
pushed to read a parameter value), you must wait 10 seconds (value is displayed for 10 seconds)
for the parameter symbol to reappear. If the parameter value was not entered, pressing Shift and
Enter together will circumvent the 10 second wait between Setup entries. The parameter
symbols appear for 10 seconds also. If another key is not pushed in 10 seconds, the display
defaults to the measurement. This feature is called timing out. To avoid timing out on any display,
push and hold Shift.
To make changes to any Configuration Setup, see “Configuration” on page 31.
30
4. Configuration
Overview
This instrument is shipped with either factory settings (default values) or user defined settings, as
specified per sales order. Table 4 on page 32 (Configuration Setup Entries) lists all the parameters
that are more frequently changed and Table 12 on page 49 (Basic Setup Entries) lists the
parameters that are calibration oriented. Both tables list the displayed symbol, the page containing
information about the parameter, a description of the display, the factory default value, and a
space in which to write user values.
Configuration is the keypad manipulation of some parameters to make the Analyzer function to
the user's specifications. This section explains how to enter and change specific data through the
keypad. Because reconfiguration may also involve wiring or jumper changes, care must be taken
to ensure that all three items are checked before the Analyzer is placed into service either at startup
or after any changes are made.
All 873 parameters are entered as 4-digit numerical codes. The code is chosen from tables shown
with each parameter. There are several parameters that are entered as direct 4-digit values.
Therefore, no table is supplied for those parameters. Successful configuration requires four simple
steps:
1. Write down all your parameters in the spaces provided on the configuration tables.
2. Unlock the instrument.
3. Enter the 4-digit codes.
4. Lock the instrument.
Configure Mode
The Configure Mode is protected through two levels of security, one level for “Configuration
Setup Entries” and two for “Basic Setup Entries.” Any configuration change starts with Unlocking
the instrument. Unlocking is accomplished by entering a security code through the keypad.
Security Code
There are two levels of security in the Analyzer. The first level of security protects against
unauthorized change of Temp, H Alm, L Alm, Cal Lo, Cal Hi, and all the “Configuration Setup
Entries” (of which there are 19) (refer to “Configuration Setup Entries” on page 32). The second
level of security protects against the remaining 22 setup entries, called “Basic Setup Entries,” 19 of
which can be changed in the field (refer to “Basic Setup Entries” on page 49).
Note that any of the parameters discussed above can be viewed when the Analyzer is in the locked
state. When displaying a parameter in the locked state, none of the digits flicker, and an attempt
to change the parameter results in the message Loc on the display.
The same security code is used to unlock the unit in both levels of security. When the unit is
unlocked at the first level (see“Unlocking Analyzer Using Security Code” on page 32), the unit
31
MI 611-168 – January 2021
4. Configuration
will remain unlocked until a positive action is taken to lock the unit again (see “Locking Analyzer
Using Security Code” on page 32).
However, when the unit is unlocked by using the bL entry at the second level of security (see
“Unlocking Basic Setup Entries (bL)” on page 50), it will remain unlocked only as long as any of
the Basic Setup Entries are being accessed. As soon as the Analyzer defaults to the current
measurement value, the second level of security automatically locks again, so an unlock procedure
is required to reaccess the Basic Setup Entries.
Unlocking Analyzer Using Security Code
1. Press Lock. Display will read Loc.
2. Press Next and then use the Next and increment (Δ) keys until the security code is
displayed (0800 from factory).
3. Press Enter. Analyzer will read uLoc, indicating unlocked state.
Locking Analyzer Using Security Code
1. Press Lock. Display will read uLoc.
2. Press Next and then use the Next and increment (Δ) keys until security code is
displayed (0800 from factory).
3. Press Enter. Analyzer will read Loc, indicating locked state.
Configuration Setup Entries
The configuration setup entries consist of 19 parameters. These parameters are process oriented
and access to them is passcode protected. Table 4 lists each parameter, with its applicable symbol,
in the same sequence as seen on the display. Descriptions of each parameter are given in the
following text.
Table 4. Configuration Setup Entries
Displayed
Symbol
Reference
Page
Parameters and Values Accessed
Factory
Default
CELL
33
Configuration of Display, Analog Outputs
1013
Hold
35
Holds and sets the Analog Output Value in Hold
0000
Cd
36
Compensation and Damping
Damping Factor
Chemical Temperature Compensation
0001
HAC
38
H Alarm Configuration
Measurement Selection
Low/High/Instrument plus Passive/Active State
% Hysteresis
1403
HAtt
39
H Alarm Trigger Time
00.00
HAFt
39
H Alarm Feed Time
00.00
HAdL
39
H Alarm Delay Time
00.00
32
User
Settings
4. Configuration
MI 611-168 – January 2021
Table 4. Configuration Setup Entries (Continued)
Displayed
Symbol
Reference
Page
Factory
Default
Parameters and Values Accessed
LAC
42
L Alarm Configuration
Measurement Selection
Low/High/Instrument plus Passive/Active State
% Hysteresis
1203
LAtt
43
L Alarm Trigger Time
00.00
LAFt
43
L Alarm Feed Time
00.00
LAdL
43
L Alarm Delay Time
00.00
UL
46
User-defined Upper Measurement Limit - Both Cells
20.00
LL
46
User-defined Lower Measurement Limit - Both Cells
00.00
UtL
47
User-defined Upper Temperature Limit - Both Cells
100.C
LtL
47
User-defined Lower Temperature Limit - Both Cells
000.C
HO1
48
100% Analog Output - Channel 1
20.00
LO1
48
0% Analog Output - Channel 1
00.00
HO2
48
100% Analog Output - Channel 2
100.C
LO2
49
0% Analog Output - Channel 2
000.C
User
Settings
To change any of the Configuration Setup parameters, use the following procedure:
1. Unlock Analyzer (see “Unlocking Analyzer Using Security Code” on page 32).
2. Press Shift and while holding, press Setup. Release fingers from both keys.
3. Press Next one or more times until the parameter to be changed is displayed
4. Press Enter.
5. Use Next and Δ until the desired code or value is displayed.
6. Press Enter.
7. Lock Analyzer (see “Configuration Setup Entries” on page 32).
NOTE
To prevent time-out while in the middle of this procedure, press/hold the SHIFT key.
CELL Display and Output Configuration (CELL)
The CELL 4-digit code selects the measurement displayed, the measurements taken (one or two),
and configures the analog output assignment. See Table 5.
33
MI 611-168 – January 2021
4. Configuration
Digit 1 Configuration:
This digit configures the Analyzer’s display, output, and measurement capabilities. The selections
are as follows.
Digit
1
Cell 1 is displayed. Cell 2 is not in use.
2
Cell 2 is displayed. Cell 1 is not in use.
3
Cell 1 is displayed. Cell 2 measurement is live. Alarms and outputs can be set for both
cells.
4
Cell 2 is displayed. Cell 1 measurement is live. Alarms and outputs can be set for both
cells.
7
Ratio is displayed when the first digit is 7. It is mathematically defined as
Cell 1
--------------- × 100 (Percent legend illuminated)
Cell 2
8
Percent Rejection is displayed when the first digit of this code is 8. Percent Rejection is
defined mathematically as
1
1 – Cell
--------------- × 100 (Percent legend illuminated)
Cell 2
When the Analyzer is configured for dual sensor measurement, (digit one = 3, 4, 7, or 8), the
Analyzer works in a switching mode, updating each sensors measurement alternately at a
1.5 second rate. The response time for 90% response is 7 seconds when dual sensors are used.
By contrast, the response time for single sensor use is 3.0 sec for 90% response.
NOTE
A cell must be configured as a measurement alarm in order for an Alarm or Output to
be configured to it successfully.
Digits 3 and 4 Configurations:
The plastic enclosure has only one analog output. Configure Digit 3 (Output 1) to correspond to
this output. With the metal enclosure, two output signals are available. Most of the output
choices in Table 5 are self-explanatory. The measurement signal can also be scaled logarithmically.
Using this approach, the output signal may be expanded in a particular range of measurement.
NOTE
Contact the application specialists at Invensys for additional information regarding
the Log output.
Possible combinations for the two outputs include:
♦ Resistivity and Temperature Sensor 1
♦ Resistivity Sensor 1 and Resistivity Sensor 2
♦ Ratio Measurement and Temperature
♦ % Rejection and Resistivity Sensor 1
34
4. Configuration
MI 611-168 – January 2021
For specific information on sensor setup, see Chapter 7, “User Notes” .
Table 5. CELL Code - Display and Output Configuration
Digit 1
Measurement And Display
1- Measures and displays Cell 1 only
2- Measures and displays Cell 2 only
3- Measures Cell 1 and Cell 2
Displays Cell 1
4- Measures Cell 1 and Cell 2
Displays Cell 2
7- Ratio
8- % Rejection
Digit 2
Digit 3
Digit 4
Not Used
Output 1
Output 2
Digit 2 is not used
and should be set
at zero.
1-Resistivity Cell 1
2-Resistivity Cell 2
3-Temp Cell 1
4-Temp Cell 2
5-Log (resistivity Cell 1)
6-Log (resistivity Cell 2)
7-Ratio
8-% Rejection
1-Resistivity Cell 1
2-Resistivity Cell 2
3-Temp Cell 1
4-Temp Cell 2
5-Log (resistivity Cell 1)
6-Log (resistivity Cell 2)
7-Ratio
8-% Rejection
Holding the Analog Output (Hold)
The 4-digit code, Hold, is used to freeze the output(s) and alarms to a particular value. The
selections are shown in Table 6. When the first digit of this code is 1, 2, or 3, the display flashes
between the word “Hold” and the present measurement value. The outputs are frozen at a value
corresponding to a % of the analog output range. This percentage is set by the last three digits of
the Hold code. While in one of the Hold modes, the Analyzer will continue to monitor and
display the value the sensor observes. The sensor may be cleaned or replaced and the unit
calibrated while in this mode. An additional use of HOLD permits the output to be simulated to
check recorder or controller settings.
If an alarm is configured as a High, Low, or Instrument alarm (HAC, or LAC; 2nd digit in code a
1-6), the alarm status while in the Hold mode may be chosen by the first digit in the Hold code.
If, for instance, an alarm is configured as a Hold alarm (HAC or LAC; 2nd digit a 7 or 8), the
alarm will trigger when the Hold is activated. This feature will allow a control room or alarm
device (light, bell, etc.) to know the Analyzer is in a Hold mode, not a “RUN” mode. The
ALARM will be activated when Hold is implemented when the first digit in the Hold code is
changed from 0 to 1, 2, or 3.
Example 1: Hold at a Percent of the Analog Output
For an Analog output of 4 to 20 mA, 50% (050) will always equal 12 mA, and 0% will equal
4 mA.
Or, to Hold on the value being displayed at the present time, the value displayed must be
converted to a percent value by the following equation:
(Value displayed - LO1)
------------------------------------------------------------- × 100
HO1 – LO1
Example 2: Hold at the value presently read on the display
The presently displayed value for Cell 1 is 17 MΩ •cm. HO1 is set at 18.5 MΩ •cm, LO1 is set at
12 MΩ •cm. To set Hold at 17, the last 2 digits of Hold must be 77.
35
MI 611-168 – January 2021
4. Configuration
17 – 12
5
----------------------- × 100 = ------- × 100 = 77
18.5 – 12
6.5
The Hold Code should read 1077, 2077, or 3077 as applicable. See “Output #1's 100% Analog
Value (HO1)” on page 48 and “Output #1's 0% Analog Value (LO1)” on page 48 for a
description of H01 and L01.
If two outputs are present, both will Hold at 77% (077) of their analog output ranges.
Table 6. Hold Code - Hold Analog Output and Alarms
Digit 1
Digits 2, 3, and 4
Hold Status
Output Range
0 - No Hold
000 to 100% of Analog Output Range
Hold ON, Analog Output on Hold
1 - Alarms held in present state
2 - Alarms held with relay not activated
3 - Alarms held with relay activated
Compensation and Damping (Cd)
Cd consists of a 4-digit code that selects the type of temperature compensation desired and the
amount of damping applied to the measurement. Damping time refers to an interval over which
all measurement readings are averaged. Damping affects the measurement and temperature
displayed and the analog outputs also. There are two possibilities to use for temperature
compensation. Absolute (Digit 4 = 0) does not include temperature compensation. The
measurement displayed will include contributions from contaminants as well as temperature. The
Ultrapure water correction applies a temperature correction to 25°C based upon the ultrapure
water characteristics at 18.2 MΩ •cm and increasing contributions from a contaminant (NaCl
assumed) as the resistivity decreases. The code selections are shown in Table 7.
Table 7. Cd Code - Compensation and Damping
Digit 1
Digit 2
Digit 3
Digit 4
Damping
Not Used
Not Used
Temperature Compensation
0 = none
1 = 10 second
2 = 20 second
3 = 40 second
4 = 80 second
5 = 160 second
Enter 0
Enter 0
0 = Absolute (no compensation)
1 = Ultrapure water temperature correction applied.
MΩ•cm resistivity is referenced to 25°C
General Information Alarms
Dual independent, Form C dry alarm contacts, rated at 3A noninductive (5A on General Purpose
panel-mounted instrument), 125 V ac/30 V dc are provided. The alarm status and measurement
36
4. Configuration
MI 611-168 – January 2021
are alternately displayed on the LED display. Alarms are set using a code for low, high, hold, or
instrument watchdog alarms, with active or passive relays, having a deadband or time delay.
Wiring information for the alarms may be found in “Wiring of Plastic Enclosure” on page 24 and
“Wiring of Metal Enclosure” on page 25 of this instruction.
! CAUTION
When the contacts are used at signal levels of less than 20 W, contact function may
become unreliable over time due to the formation of an oxide layer on the contacts.
See “Alarm Contact Maintenance” on page 87.
NOTE
1. Alarms will have to be reset if any changes are made to Full Scale Range.
2. Upon powering the Analyzer, the alarm operation is delayed for a time period
proportional to the amount of damping set in the Cd code. The alarms remain
“OFF” until this measurement has stabilized.
Check that the alarm is configured as desired. Refer to “H Alarm Configuration (HAC)” on
page 38 and “L Alarm Configuration (LAC)” on page 42.
Figure 13. Possible Alarm Wiring and Configuration Choices
Configured Passive – When activated, relay is energized and
local display indicates alarm state.
NO
Second
digit in LAC
or HAC 1, 3,
5, or 7
No Alarm indication
on local display
C
NC
NO
NO
C
ON
NC
ON
C
Alarm indication
on local display
NC
NO
C
NC
Configured Active – When activated, relay is not energized and
local display indicates alarm state.
NO
ON
Second
digit in LAC
or HAC 2, 4,
6, or 8
C
NO
No Alarm indication
on local display
NC
NC
“Failsafe Operation”
NO
NO
C
NC
C
Alarm indication
on local display
C
NC
ON
Setting Alarm Level(s)
NOTE
This procedure is relevant only when the alarms are configured as measurement Low
and/or High Alarms. When the alarms are configured as Watchdog or Hold alarms,
alarm level settings have no relevance.
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MI 611-168 – January 2021
4. Configuration
1. Unlock Analyzer (see “Unlocking Analyzer Using Security Code” on page 32).
2. To set high alarm, press H Alm. Then use Next and Δ to achieve the desired value on
the display.
3. Press Enter.
4. To set low alarm, press L Alm. Then use Next and Δ to achieve the desired value on
the display.
5. Press Enter.
6. Lock Analyzer (see “Locking Analyzer Using Security Code” on page 32).
NOTE
If alarms are not desired, set the H Alm and L Alm values outside the normal
measurement range.
H Alarm Configuration (HAC)
The HAC 4-digit code configures the alarm designated as “H Alm.” See Table 8 on page 39.
There are three configurable parameters associated with each alarm. The first digit of this code
allows the alarm to be configured to correspond to one of six alarm measurement selections. The
second digit of this code configures the alarm as a Measurement alarm, Instrument alarm, or
Hold alarm. The third and forth digits set the alarm hysteresis (deadband). This parameter is
associated with the alarms used as measurement alarms. The deadband may be varied from 0 to
99% of the FSC range in increments of 1%.
When used as a measurement alarm, four configurations are possible. These are as a low passive or
active, or a high passive or active alarm, i.e., digit 2 is 1-4.
A low alarm relay will trip on decreasing measurement.
A high alarm relay will trip on increasing measurement.
Passive or active (failsafe) configurations are also chosen by this digit choice. In the active (failsafe)
configuration, a loss of power to the Analyzer causes a change from active to passive relay state,
providing contact closure and an indication of a power problem. Correct wiring of the contacts is
necessary for true failsafe operation. Consult “Wiring of Plastic Enclosure” on page 24 and
“Wiring of Metal Enclosure” on page 25 of this document for wiring information. Also see
Figure 13 on page 37.
As an alternative to a measurement alarm, the H alarm may be used as an Instrument Alarm. In
this “Watchdog” state, the alarm can communicate any diagnostic error present in the system.
When used as a diagnostic alarm, the H alarm cannot be used as a conventional measurement
alarm. However, since one of the configurable diagnostic parameters is “measurement error,” the
H alarm, when programmed properly, can report either diagnostic or measurement problems. Set
digit 2 in this code as either 5 or 6, as applicable.
When the H alarm is configured as a diagnostic error communicator, it will report any system
problem. It cannot selectively report a given problem, however. The type of hardware/software
conditions that will cause an alarm include:
♦ A/D converter error
♦ EEPROM checksum error
38
4. Configuration
MI 611-168 – January 2021
♦ RAM error
♦ ROM error
♦ Processor task time error (watchdog timer)
Additionally, the user may program several temperature and measurement error limits that, if
exceeded, will cause an alarm condition. These programming options are explained in “UserDefined Upper Temperature Limit (UtL)” on page 47 and “User-Defined Lower Temperature
Limit (LtL)” on page 47.
Refer to the “Error Codes” on page 75 for identifying error messages.
The H alarm may also be configured and used as a Hold alarm. When used as a Hold alarm, the
H alarm cannot be used as a conventional measurement alarm. When the alarm is configured as a
HOLD alarm (HAC; 2nd digit a 7 or 8), the alarm will trigger when the Hold is activated. This
feature will allow a control room or alarm device (light, bell, etc.) to know the Analyzer is in a
Hold mode, not a “RUN” mode. The ALARM will be activated when Hold is implemented when
the first digit in the Hold code is 1, 2, or 3.
NOTE
The cell must be configured in a measurement state for the alarm to be configured
and operative. If an unused cell in the single cell mode is configured to the alarm, the
alarm will be inoperative (frozen at 4 mA). Verify that the cell code is set
appropriately. See “CELL Display and Output Configuration (CELL)” on page 33.
Table 8. HAC Code - High Alarm Configuration
Digit 1
Digit 2
Digits 3 and 4
H ALARM
SELECTION
CONFIGURATION
HYSTERESIS
1 - Meas Cell 1
2 - Meas Cell 2
3 - Temp Cell 1
4 - Temp Cell 2
7 - % Ratio
8 - % Rejection
1 = Low/Passive
2 = Low/Active
3 = High/Passive
4 = High/Active
5 = Instrument/Passive
6 = Instrument/Active
7 = Hold/Passive
8 = Hold/Active
00 to 99% of Full Scale
Alarm Timers (HAtt, HAFt and HAdL)
There are three timers associated with the H Alarm:
1. HAtt (H Alarm Trigger Time)
Programmable timer to prevent alarm from triggering unless the measurement
remains in the alarm state for a user-defined period of time.
2. HAFt (H Alarm Feed Time)
Programmable timer to keep alarm ON for a user-defined period of time once it has
been tripped.
3. HAdL (H Alarm Delay Time)
Programmable timer to keep the alarm OFF for a user-defined period of time once the
HAFt time has expired.
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MI 611-168 – January 2021
4. Configuration
Each of these timers will be explained fully in the following paragraphs and their relationships
illustrated in Figure 14 and the flow diagram in Figure 15.
H Alarm Trigger Timer (HAtt) may be used with or without the other alarm timers (HAFt and
HAdL). HAtt is used when H Alarm is configured as a measurement alarm only. The purpose of
this timer is to prevent the alarm from activating due to transient conditions such as air bubbles or
other spikes. After the timer has counted down, that alarm will activate only if the measurement
has remained in an alarm state during the entire trigger time. HAtt resets any time the
measurement passes through the alarm set point. Table 9 on page 40 shows the code designation.
H Alarm Feed Time (HAFt) is activated by entering a time in the code parameter HAFt. When the
H Alarm is triggered, the alarm will remain ON for this time period regardless of what the
measurement value is with respect to the alarm set point (i.e., H Alarm will remain ON even if
the measurement returns to normal). Table 9 shows the code designation.
H Alarm Delay Time (HAdL) is activated by entering a time in the code parameter HAdL. Upon
time-out of HAFt, the alarm will stay OFF for this time period regardless of what the
measurement value is with respect to the alarm set point (the H Alarm will remain OFF even if
the measurement goes back into alarm). Table 9 shows the code designation.
Table 9. HAtt, HAFt, and HAdL Time Codes
Digits 1 and 2
00 to 99 minutes
Digit 3
0 to 9 tenths of minutes
Digit 4
0 to 9 hundredths of minutes
Examples:
05.15 means 5 minutes, 9 seconds
20.50 means 20 minutes, 30 seconds
After time-out of HAdL, the 873 reverts to normal run mode. If the measurement has remained
in an alarm state for the entire period (HAFt + HAdL), the sequence of HAFt and HAdL repeats
itself. If, however, the measurement has gone out of alarm at any time during the cycle, it must
remain in alarm for the trigger time before reactivating the cycle.
40
4. Configuration
MI 611-168 – January 2021
Figure 14. ON/OFF Relationship between HAtt, HAFt and HAdL
a
f
SetPoint
b
g
h
Measurement
ON
e
c
a
h
Alarm Relay
b
OFF
ON
d
g
OFF
HAtt (5 min.)
a
ON
e
OFF
HAFt (15 min)
ON
e
OFF
HAdL (20 min)
0
10
20
30
40
Minutes
50
60
70
The following explanatory notes coupled with the illustration above should serve to demonstrate
the function of the three 873 Analyzer timers.
a. Measurement exceeds set point but does not remain above set point for the time
period set in HAtt (5 minutes). Alarm relay remains inactive. Note that HAtt
resets when the measurement falls below set point.
b. Measurement exceeds set point once again. activating HAtt, and remains
continuously above set point for the time period set in HAtt (5 minutes).
c. After measurement has remained above set point for the entire trigger time
(5 minutes), the alarm relay is activated.
d. HAtt is reset when measurement falls below set point once again. Note that the
alarm relay remains activated despite the fact that the measurement has fallen
below the set point. The alarm relay will remain activated for the time period set
in HAFt (15 minutes).
e. After the alarm relay has been activated for the feed time (15 minutes), HAFt
times out and the alarm relay is deactivated. The alarm relay will remain
deactivated for the time period set in HAdL (20 minutes).
f. Measurement exceeds set point, but the alarm relay remains deactivated because
the delay time (20 minutes) has not expired.
g. After the delay time has expired, the measurement is still in alarm, so HAtt is
activated.
41
MI 611-168 – January 2021
4. Configuration
h. The measurement drops below set point before the trigger time (5 minutes)
expires, so the alarm relay does not activate and HAtt is reset.
The following flow diagram should also serve to illustrate the logic of the three alarm timers:
Figure 15. Flow Diagram for Alarm Timer Logic
No
Measurement
exceed alarm
set point?
HAtt
Measurement
Start
here
Yes
No
Above alarm
set point continuously
for HAtt
HAFt
Yes
HAdL
Measurement
exceed alarm set point
continuously for
HAFt + HAdL
Yes
No
L Alarm Configuration (LAC)
The LAC 4-digit code configures the L alarm. See Table 10 on page 43. Three configurable
parameters are associated with this alarm. The first digit of this code allows the alarm to be
configured to correspond to one of six alarm measurement selections. The second digit of the
code configures the alarm as a Measurement alarm, Instrument alarm, or Hold alarm.
The third and forth digits set the alarm hysteresis (deadband). This parameter is associated with
the alarm when used as a measurement alarm. The deadband may be varied from 0 to 99% of
FSC range chosen in increments of 1%.
When used as a measurement alarm, four configurations are possible. These are as a low passive or
active, or a high passive or active alarm. Set digit 2 as 1-4, as applicable.
A low alarm relay will trip on decreasing measurement.
A high alarm relay will trip on increasing measurement.
Passive or active (failsafe) configurations are also chosen by this digit choice. In the active (failsafe)
configuration, a loss of power to the Analyzer will result in a change from active to passive relay
state, providing contact closure and an indication of a power problem. Correct wiring of the
contacts is necessary for true failsafe operation. Consult “Wiring of Plastic Enclosure” on page 24
and “Wiring of Metal Enclosure” on page 25 of this document for wiring information. Also see
Figure 13 on page 37.
Alternative to a measurement alarm, the L alarm may be used as an Instrument Alarm. In this
“Watchdog” state, the alarm can communicate any diagnostic error present in the system. When
used as a diagnostic alarm, the L alarm cannot be used as a conventional measurement alarm.
42
4. Configuration
MI 611-168 – January 2021
However, since one of the configurable diagnostic parameters is “measurement error,” the L alarm,
when properly programmed, can report either diagnostic or measurement problems. Set digit 2 in
this code as either a 5 or 6, as applicable.
When the L alarm is configured as a diagnostic error communicator, it will report any system
problem. It cannot selectively report a given problem. The type of hardware/software conditions
that will cause an alarm include:
♦ A/D converter error
♦ EEPROM checksum error
♦ RAM error
♦ ROM error
♦ Processor task time error (watchdog timer)
Additionally, the user may program several temperature and measurement error limits which, if
exceeded, will cause an alarm condition. These programming options are explained in “UserDefined Upper Temperature Limit (UtL)” on page 47 and “User-Defined Lower Temperature
Limit (LtL)” on page 47.
Refer to the “Error Codes” on page 75, for identifying error messages.
The L alarm may also be configured and used as a Hold alarm. When used as a Hold alarm, the L
alarm cannot be used as a conventional measurement alarm. When the L alarm is configured as a
Hold alarm (LAC; 2nd digit a 7 or 8), the alarm will trigger when the Hold is activated. This
feature will allow a control room or alarm device (light, bell, etc.) to know the Analyzer is in a
Hold mode, not a “RUN” mode. The ALARM will be activated when Hold is implemented when
the first digit in the Hold code is 1, 2, or 3.
NOTE
Configuration of the alarm to a cell not in a measurement state will result in nonoperation of the alarm. Verify cell code is set appropriately. See “CELL Display and
Output Configuration (CELL)” on page 33.
Table 10. LAC Code - Low Alarm Configuration
Digit 1
Digit 2
Digits 3 and 4
L ALARM SELECTION
CONFIGURATION
HYSTERESIS
1 - Meas Cell 1
2 - Meas Cell 2
3 - Temp Cell 1
4 - Temp Cell 2
7 - % Ratio
8 - % Rejection
1 = Low/Passive
2 = Low/Active
3 = High/Passive
4 = High/Active
5 = Instrument/Passive
6 = Instrument/Active
7 = Hold/Passive
8 = Hold/Active
00 to 99% of Full Scale
Alarm Timers (LAtt, LAFt, and LAdL)
There are three timers associated with the L Alarm:
1. LAtt (L Alarm Trigger Time)
Programmable timer to prevent alarm from triggering unless the measurement
remains in the alarm state for a user-defined period of time.
43
MI 611-168 – January 2021
4. Configuration
2. LAFt (L Alarm Feed Time)
Programmable timer to keep alarm ON for a user-defined period of time once it has
been tripped.
3. LAdL (L Alarm Delay Time)
Programmable timer to keep the alarm OFF for a user-defined period of time once the
LAFt time has expired.
Each of these timers will be explained fully in the following paragraphs and their relationships
illustrated in Figure 16 and the flow diagram in Figure 17 on page 46.
L Alarm Trigger Timer (LAtt) may be used with or without the other alarm timers (LAFt and
LAdL). LAtt is used when L Alarm is configured as a measurement alarm only. The purpose of this
timer is to prevent the alarm from activating due to transient conditions such as air bubbles or
other spikes. After the timer has counted down, that alarm will activate only if the measurement
has remained in an alarm state during the entire trigger time. LAtt resets any time the
measurement passes through the alarm set point. Table 11 shows the code designation.
L Alarm Feed Time (LAFt) is activated by entering a time in the code parameter LAFt. When the
L Alarm is triggered, the alarm will remain ON for this time period regardless of what the
measurement value is with respect to the alarm set point (i.e., L Alarm will remain ON even if the
measurement returns to normal). Table 11 shows the code designation.
L Alarm Delay Time (LAdL) is activated by entering a time in the code parameter LAdL. Upon
time-out of LAFt, the alarm will stay OFF for this time period regardless of what the
measurement value is with respect to the alarm set point (i.e., L Alarm will remain OFF even if
the measurement goes back into alarm). Table 11 shows the code designation.
Table 11. LAtt, LAFt, and LAdL Time Codes
Digits 1 and 2
00 to 99 minutes
Digit 3
0 to 9 tenths of minutes
Digit 4
0 to 9 hundredths of minutes
Examples:
05.15 means 5 minutes, 9 seconds
20.50 means 20 minutes, 30 seconds
After time-out of LAdL, the 873 reverts to normal run mode. If the measurement has remained in
an alarm state for the entire period (LAFt + LAdL), the sequence of LAFt and LAdL repeats itself.
If, however, the measurement has gone out of alarm at any time during the cycle, it must remain
in alarm for the trigger time before reactivating the cycle.
44
4. Configuration
MI 611-168 – January 2021
Figure 16. ON/OFF Relationship between LAtt, LAFt, and LAdL
a
f
SetPoint
b
g
h
Measurement
ON
e
c
a
h
Alarm Relay
b
OFF
ON
d
g
OFF
LAtt (5 min.)
a
ON
e
OFF
LAFt (15 min)
ON
e
OFF
LAdL (20 min)
0
10
20
30
40
Minutes
50
60
70
The following explanatory notes coupled with the illustration above demonstrate the functions of
the three 873 Analyzer timers.
a. Measurement drops below set point but does not remain below set point for the
time period set in LAtt (5 minutes). Alarm relay remains inactive. Note that LAtt
resets when the measurement rises above set point.
b. Measurement drops below set point once again. activating LAtt, and remains
continuously below set point for the time period set in LAtt (5 minutes).
c. After measurement has remained below set point for the entire trigger time
(5 minutes), the alarm relay is activated.
d. LAtt is reset when measurement rises above set point once again. Note that the
alarm relay remains activated despite the fact that the measurement has risen
above the set point. The alarm relay will remain activated for the time period set
in LAFt (15 minutes).
e. After the alarm relay has been activated for the feed time (15 minutes), LAFt
times out and the alarm relay is deactivated. The alarm relay will remain
deactivated for the time period set in LAdL (20 minutes).
f. Measurement drops below set point, but the alarm relay remains deactivated
because the delay time (20 minutes) has not expired.
g. After the delay time has expired, the measurement is still in alarm, so LAtt is
activated.
45
MI 611-168 – January 2021
4. Configuration
h. The measurement rises above set point before the trigger time (5 minutes) expires,
so the alarm relay does not activate and LAtt is reset.
The following flow diagram should also serve to illustrate the logic of the three alarm timers:
Figure 17. Flow Diagram for Alarm Timer Logic
Measurement
below alarm
set point?
No
LAtt
Measurement
No
Start
here
Yes
Below alarm
set point continuously
for LAtt?
LAFt
Yes
LAdL
Measurement
below alarm set point
continuously for
LAFt + LAdL?
Yes
No
User-Defined Upper Measurement Limit (UL)
This enables the user to define an upper measurement limit which, if exceeded, will give an error
message on the display (see “Error Codes” on page 75), and when used with either alarm
configured as an instrument (watchdog) alarm (HAC or LAC digit 2 is 5 or 6), provides a relay
contact. The value set by this code defines the measurement limit for both cells.
UL is primarily used as a sensor diagnostic tool. If the 871CC sensor develops a fault, such as
leakage between the electrodes or a broken or intermittent lead wire, the measurement signal sent
to the 873 Analyzer will be unreasonably low or high. By setting UL at a value that could never be
achieved in a normal process situation, such as 19 MΩ •cm, activation of a UL alarm indicates
either a severe sensor failure or miscalibration. The upper limit of UL is 99.99 MΩ •cm.
NOTE
Invensys preconfigures UL to a value equal to the specified full scale measurement per
Sales Order.
User-Defined Lower Measurement Limit (LL)
The LL parameter is similar to the previously described UL parameter, except that it allows
programming of a lower measurement limit. In an ultrapure water measurement application, a
value of 0 ΜΩ •cm is a good choice for LL, since ultrapure water could never actually reach a
resistivity value as low as 0. The lower limit on LL is –.999 MΩ •cm (decimal point will move
with the FSC range used). The value set by this parameter is related to both measurement cells.
46
4. Configuration
MI 611-168 – January 2021
NOTE
To make a minus sign appear on the display requires a digit other than zero to be
present on the display
Example:
To make the display read -.99, first display 0.99, then change the first digit to a negative sign.
User-Defined Upper Temperature Limit (UtL)
This parameter enables the user to define an upper temperature measurement value which, if
exceeded, gives an E3 message on the display (see “Error Codes” on page 75). When used in
conjunction with the configurable alarms (HAC or LAC digit 2 is 5 or 6), it provides a relay
contact.
UtL is primarily used as a sensor diagnostic tool. If the RTD or thermistor in the 871CC sensor
develops a fault, the instrument may produce erroneous temperature readings at either extreme of
the temperature scale. By setting UtL at a temperature outside any conceivable process
temperature, an alarm indicates a problem with the 871CC sensor temperature transducer. The
upper limit of UtL is 200°C or 392°F.
The value set for this parameter defines the limit for both sensors (if installed).
User-Defined Lower Temperature Limit (LtL)
This parameter is similar to the previously described UtL parameter, except that it allows
programming of a lower temperature measurement limit. The lower limit on LtL is –20°C or
–5°F. Invensys preconfigures the LtL value to be 0°C. The value set for this parameter defines the
limit for both sensors (if installed).
NOTE
To make a minus sign appear on the display requires that a digit other than zero be
present on the display. Example: To make the display read -20°C, first display 020°C,
then change the first digit to a negative sign.
Scaling Analog Outputs
Each 873RS Analyzer has either one or two analog output signals as standard. Each output signal
is linearly proportional to the measured variable (except when the output(s) is (are) configured as
logarithmic. (Refer to “CELL Display and Output Configuration (CELL)” on page 33).
Both analog output signals may be scaled so as to improve sensitivity of the analog output within
the range of interest. The outputs can be scaled as forward or reverse acting. The output
configuration will be ignored, frozen at 4mA, if the CELL code is not configured properly. If an
output is to be configured to a cell, the cell must be in an active measurement state. See “CELL
Display and Output Configuration (CELL)” on page 33.
The maximum output span that should be set on the Analyzer is the FSC value. The minimum
output span that should be set on the Analyzer is 10% of the FSC value. Although it is physically
47
MI 611-168 – January 2021
4. Configuration
possible to set the Analyzer for a smaller span, a loss of accuracy is possible. The analog output
could develop steps instead of following the measurement in a continuum.
NOTE
The analog outputs should be configured after the FSC and Cd parameters have been
set.
Output #1's 100% Analog Value (HO1)
This 4-digit code may be set to any value between –0.99 and 99.99. The value set by this code
will correspond to 100% of the analog output (20 mA or 10 volts), depending upon output
ordered.
Example:
Output 1 has been configured to correspond to the resistivity of Cell 1 (CELL Code 1013). You
want 20 mA to correspond to 15 MΩ •cm. Once in H01 mode, use Next and Δ to display the
correct value 15.00 MΩ •cm. Press Enter. The correct units will appear if CELL was configured
properly.
Output #1's 0% Analog Value (LO1)
This 4-digit code may be set to any value between –0.99 and 99.99. The value set by this code
will correspond to 0% of the analog output, that is, 0 mA, 4 mA, or 0 V, depending upon the
output configuration. The value may be greater than H01 if desired. The L01 value is tied to
CELL code digit 3.
Example:
Output 1 has been configured to correspond to the resistivity of Cell 1 (CELL Code 1013). You
want 4 mA to correspond to 5.00 MΩ •cm. Once in L01 mode, use Next and Δ to display
5.00 MΩ •cm. Press Enter. The correct units will appear if CELL was configured properly.
Output #2's 100% Analog Value (H02)
NOTE
Only use on metal units; general purpose units use H01.
H02 configures the second output to 100% of the analog output. The parameter is similar to
H01. The H02 value ties to CELL code digit 4.
Example:
Output 2 has been configured to correspond to the temperature transducer of Cell 1 (CELL Code
1013). You wish to have 20 mA correspond to 30°C. Once in H02 mode, use Next and Δ to
display 30°C. Press Enter. The correct units will appear if CELL was configured properly.
48
4. Configuration
MI 611-168 – January 2021
Output #2's 0% Analog Value (L02)
NOTE
Only use on metal units; general purpose units use L01.
L02 configures the second output to 0% of the analog output. This parameter is similar to L01.
The L02 value ties to CELL code digit 4.
Example:
Output 2 has been configured to correspond to the temperature transducer of Cell 1 (CELL Code
1013). You wish to have 4 mA correspond to 100°C. Once in L02 mode, use Next and Δ to
display 100°C. Press Enter. The correct units will appear if CELL was configured properly.
Basic Setup Entries
The Basic Setup entries consist of 19 configurable parameters. These parameters are calibration
oriented and access to them has two levels of passcode protection. Changes to most of these
parameters require the Analyzer to be recalibrated. DO NOT make any changes before reading
the following text for each parameter.
Table 12 lists all parameters, with applicable symbols, in the same sequence as seen on the display.
Descriptions of the procedures that use these parameters (Unlocking Basic Setup Entries,
Changing the Full Scale Range, Changing the Temperature Circuitry, Changing the Analog
Output, and Changing the Security Code) follow the table.
Table 12. Basic Setup Entry Selection
Display
Symbol
Reference
Parameter and Value Accessed
Factory
Default
bL
50
Basic Setup Lock Control
0800
FSC
50
Full Scale Value
20.00
CF1
69
Cell Factor - Cell 1
1000
tCF1
69
Temperature Cell Factor - Cell 1
25.00
tEC1
54
Thermistor Temperature Electronics Calibration Cell 1
25.00
tCL1
55
RTD Low Temperature Electronics Calibration Cell 1
100.0
tCC1
55
RTD Mid Temperature Electronics Calibration Cell 1
150.0
tCH1
55
RTD High Temperature Electronics Calibration Cell 1
200.0
LCC
62
Lock Code Change
0800
CF2
69
Cell Factor - Cell 2
1000
tCF2
69
Temperature Cel Factor - Cell 2
25.00
tEC2
54
Temperature Channel Electronics Calibration Cell 2
25.00
tCL2
55
RTD Low Temperature Electronics Calibration Cell 2
100.0
tCC2
55
RTD Mid Temperature Electronics Calibration Cell 2
150.0
tCH2
55
RTD High Temperature Electronics Calibration Cell 2
200.0
LCO1
57
Analog Out 1 Electronics Lower Calibration
00.00
HCO1
57
Analog Out 1 Electronics Upper Calibration
100.0
LCO2
57
Analog Out 2 Electronics Lower Calibration
00.00
HCO2
57
Analog Out 2 Electronics Upper Calibration
100.0
SFt
User
Settings
Software Version Number
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MI 611-168 – January 2021
4. Configuration
Table 12. Basic Setup Entry Selection (Continued)
Display
Symbol
Reference
Parameter and Value Accessed
SOH
Sales Order High
SOL
Sales Order Low
Factory
Default
User
Settings
Unlocking Basic Setup Entries (bL)
To change any of the Basic Setup Entries, use the following procedure.
NOTE
To avoid “timing out” on any display, press/hold Shift.
1. Unlock Analyzer at the first security level (see “Unlocking Analyzer Using Security
Code” on page 32).
2. Press Shift and while holding, press Setup. Release finger from both keys.
3. Press Next nineteen times until bL is displayed.
4. Press Enter. LOC appears on the display.
5. Press Next.
6. Use Next and Δ repeatedly until the security code is displayed (0800 from factory).
7. Press Enter. ULOC appears on the display.
8. When display returns to bL, press Next one or more times until parameter to be
changed appears on the display.
9. Press Enter.
10. Use Next and Δ repeatedly until the desired value is displayed.
11. Press Enter.
12. When display defaults to the current measurement value, the Analyzer is automatically
locked at the second level (bL) of security.
13. Lock Analyzer (see “Locking Analyzer Using Security Code” on page 32).
Changing the Full Scale Range (FSC)
This parameter allows the user to select one of five possible ranges to monitor the process. The
ranges are 0 to 2.000 MΩ •cm, 0 to 5.000 MΩ •cm, 0 to 10.00 MΩ •cm, 0 to 15.00 MΩ •cm, and
0 to 20.00 MΩ •cm. The Analyzer accuracy is 0.5% of the measurement range value chosen when
calibrated with precision resistors with 0.1% accuracy. Thus, for best accuracy, the FSC value
should be set as low as possible while still allowing all measurement values to fall within its span.
On the lower ranges, the Analyzer displays values to the thousandths place.
! CAUTION
1. When changing ranges, the drive voltage to the sensor inputs is changed. Altering
the FSC range via the keypad will require the unit to be bench calibrated before use.
2. Pressing Enter in FSC mode (even if range was not changed) will require the unit
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4. Configuration
MI 611-168 – January 2021
to be bench calibrated before use. If the range is set at a range you require, allow unit
to time out. Do not press Enter.
3. After changing FSC, Configuration Setup Entries should be checked and altered, if
necessary.
The Analyzer is capable of displaying values greater than that set by the FSC ranges. For example,
when the FSC is on the 0 to 5.000 MΩ •cm range, it can display up to 9.999 MΩ •cm at 25.0°C.
The FSC value is preconfigured according to the specific sales order or at 20.00 MΩ•cm as a
default.
The procedure for changing FSC is as follows:
1. Unlock the Analyzer (see “Unlocking Analyzer Using Security Code” on page 32).
2. While holding down Shift, press Setup, and then release both keys.
3. Press Next several times until the code bL (Basic Setup Lock) is displayed (bL is the
nineteenth message to be displayed).
4. Press Enter, then press Next and Δ repeatedly until personal security code is displayed
(0800 from factory).
5. Press Enter.
6. When the display returns to bL, press Next. The code FSC (Full Scale Range Change)
is displayed.
7. Press Enter. The present full scale range is displayed.
! CAUTION
If this is your desired FSC, allow unit to time out. DO NOT PRESS ENTER.
Entering any FSC causes Er4 to flash on the display, necessitating a bench calibration.
8. Press Δ repeatedly until the desired range is displayed.
9. Press Enter.
10. Lock the Analyzer (see “Locking Analyzer Using Security Code” on page 32).
NOTE
Calibration is required after full scale range is changed. Error code ER4 flashes
until calibration is accomplished. Refer to “Electronic Bench Calibration” on page 63.
Changing the Temperature Circuitry
Temperature Electronics Calibration for either thermistor (tEC1, tEC2) or RTD (tCL1, tCC1
and tCH1 or tCL2, tCC2, and tCH2) type sensors is performed at the factory. It is not necessary
to perform these procedures in the field unless:
1. You have switched from RTD type sensors (871CC Series K through M) to
thermistor type (871CC Series A through F) or vice versa.
2. You suspect a problem with the temperature calibration.
3. You wish to verify temperature electronics calibration.
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4. Configuration
NOTE
The factory calibration of these circuits uses resistors with 0.01% accuracy. Using less
accurate resistors to calibrate this instrument will reduce the accuracy specifications of
the instrument.
If you need to perform a more precise calibration, it is recommended that you
purchase the specified precision (0.01%) resistors.
If switching from an 871CC A through F style sensor (Thermistor) to an 871CC K through M
style sensor (RTD) or vice versa, it is necessary to position the jumpers within the Analyzer and
perform a recalibration.
This procedure only calibrates the Analyzer. To compensate for sensor cable length, see
“Calibrating the Analyzer to a Specific Sensor” on page 69.
To Reposition Jumpers:
! CAUTION
Use proper ESD precautions when opening this instrument for any servicing.
1. Remove power to the unit.
2. On the plastic enclosure: remove optional rear cover. Remove the four screws holding
back panel in place.
On the metal enclosure: remove the four front corner screws holding the display panel
in place. Remove rear cover. Disconnect the green earth (ground) cable; then feed wire
from sensors and power connection through seals to allow free movement of circuit
boards.
! CAUTION
The four screws are self-tapping and have a limited grip if repeatedly removed. Do not
repeatedly remove and tighten these screws.
3. Slide circuit assembly out to access the upper circuit board designated AS700EA. The
plastic enclosure slides out from the rear of its housing. The metal enclosure slides out
from the front of its housing.
4. Refer to Figure 18 on page 54 to identify jumper locations.
5. Use Table 13 to locate appropriate jumper positions.
Table 13. Jumper Positions for Temperature Transducer
Jumper
100 Ω RTD
Cell One
J12
J14
P2 & P3
P1 & P2
P1 & P2
P2 & P3, P4 & P5
Cell Two
J11
J13
P2 & P3
P1 & P2
P1 & P2
P2 & P3, P4 & P5
6. Move each jumper to its appropriate position.
7. Replace board assembly inside unit.
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Thermistor
4. Configuration
MI 611-168 – January 2021
! CAUTION
On the plastic enclosure, a string must be rigged through the loop in the ribbon cable
such that when the board assembly is slid into the housing, the string/ribbon cable
may be pulled back simultaneously, thus preventing damage to the cable. See
Figure 18 on page 54.
8. Replace cover. On metal enclosures, use Loctite (Part No. S0106ML) on the threads
of the front bezel screws, and Lubriplate (Part No. X0114AT) on the threads of the
rear cover screws.
9. If you changed to Thermistor Temperature Compensation, see “Thermistor
Temperature Electronic Calibration (tEC1, tEC2)” on page 54 to complete the
calibration.
10. If you changed to RTD Temperature Compensation, see “RTD Temperature
Calibration (tCL1, tCC1, tCH1, and tCL2, tCC2, tCH2)” on page 55.
11. Make appropriate changes to the Analyzer identification label.
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4. Configuration
Figure 18. Jumpers for Temperature Compensation
JUMPER
NUMBER
J13
100 OHM
THERMISTOR
RTD
CELL ONE
J12
J14
P2 & P3
P1 & P2
P1 & P2
P2 & P3,
P4 & P5
CELL TWO
J11
J13
P2 & P3
P1 & P2
P1 & P2
P2 & P3,
P4 & P5
1
2
3
4
5
J14
1
2
3
4
5
J12
J11
1
2
3
1
2
3
Thermistor Temperature Electronic Calibration (tEC1, tEC2)
NOTE
Sensor Styles 871CC A-F use 100 k Ω thermistors.
Required: Two 100 kΩ precision resistors with .01% accuracy or better.
1. Disconnect sensor lead connections 3, 3A, 4, and 5 from TB2.
2. Connect two precision 100 kΩ resistors between the sensor terminals:
3 and 3A, and also 4 and 5.
3. Unlock Analyzer using security code.
4. While holding down Shift, press Setup, and then release both keys.
5. Press Next several times until the code bL (Basic Lock Setup) is displayed (bL will be
the nineteenth message displayed).
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4. Configuration
MI 611-168 – January 2021
6. Press Enter, then use Next and Δ repeatedly until the personal security code is
displayed (0800 from factory).
7. Press Enter.
8. When display returns to bL, press Next 4 times until tEC1 is displayed.
9. Press Enter. The value 25.00 will be displayed.
10. Press Enter.
11. When display returns to tEC1, press Next seven times until tEC2 is displayed.
12. Press Enter. The value 25.00 will be displayed.
13. Press Enter.
14. Disconnect 100 kΩ resistors from terminals 3 and 3A. Also 4 and 5.
15. Reconnect sensor leads to 3, 3A, 4, and 5.
16. Lock the Analyzer.
This completes the thermistor temperature electronics calibration.
Figure 19. Thermistor Temperature Simulation (Metal Enclosure Shown)
100 kΩ Resistors
1 2 3 3A 4 5 6 7
2- 2+ 1- 1+
TB4
TB2
TB1
TB3
NC C NO NC C NO
LO
HI
RTD Temperature Calibration (tCL1, tCC1, tCH1, and tCL2, tCC2,
tCH2)
NOTE
871CC Sensors Type K-M use 100 Ω RTDs.
Required: two each, 100, 150, and 200 Ω precision resistors with 0.01% accuracy. Decade boxes
with cable leads will reduce calibration accuracy.
1. Disconnect sensor lead connections 3, 3A, 4, and 5 from TB2.
2. Connect two 100 Ω precision resistors between terminals:
3 and 3A, also 4 and 5.
3. Unlock Analyzer using security code.
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4. Configuration
4. While holding down Shift, press Setup, and then release both keys.
5. Press Next several times until the code bL (Basic Lock Setup) is displayed.
6. Press Enter, then use Next and Δ repeatedly until the personal security code is
displayed (0800 from factory).
7. Press Enter.
8. When display returns to bL, press Next five times until tCL1 is displayed. Press
Enter. Then keep finger on Shift.
9. Display will show 100.0 ohms. Press Shift and hold for 20 seconds, then press
Enter. Then keep finger on Shift.
10. Replace the 100 Ω resistor for cell 1 (leads 3 and 3A) with a 150 Ω precision resistor.
11. Release Shift key. When display returns to tCL1, press Next once to display tCC1.
Press Enter.
12. Display will show 150.0 ohms. Press Shift and hold for 20 seconds, then press
Enter. Then keep finger on Shift.
13. Replace the 150 Ω resistor for cell 1 with a 200 Ω precision resistor.
14. Release Shift key. When display returns to tCC1, press Next once to display tCH1.
Press Enter.
15. Display will show 200 ohms. Press Shift and hold for 20 seconds, then press Enter.
16. When display returns to tCH1, press Next five times to display tCL2. Press Enter.
17. Display will show 100.0 ohms. Press Shift and hold for 20 seconds, then press
Enter. Keep finger on Shift.
18. Replace the 100 Ω resistor for cell 2 with a 150 Ω precision resistor.
19. Release the Shift key. When display returns to tCL2, press Next once to display
tCC2. Press Enter.
20. Display will show 150.0 ohms. Press Shift and hold for 20 seconds, then press
Enter. Then keep finger on Shift.
21. Replace the 150 Ω resistor for cell 2 with a 200 Ω precision resistor.
22. Release Shift key. When display returns to tCC2, press Next once to display tCH2.
Press Enter.
23. Display will show 200.0 ohms. Press Shift and hold for 20 seconds, then press
Enter.
This completes the RTD Temperature Calibration.
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4. Configuration
MI 611-168 – January 2021
Figure 20. RTD Temperature Simulation (Plastic Enclosure Shown)
TB2
1
2
3
3A
4
5
6
7
TEMP FOR
CELL 1
TEMP FOR
CELL 2
TB1
G L2/N L1
TB3
M
+
M
-
1
N
O
7
C
1
N
C
2
N
O
2
C
2
N
C
Changing the Analog Output
To change one or both of your analog outputs to a different output than the Analyzer was ordered
with, jumpers must be moved and a recalibration performed.
To Reposition Jumpers
! CAUTION
Use proper ESD precautions when opening this instrument for any servicing.
1. Remove power to the unit.
2. On the plastic enclosure, remove optional rear cover. Remove the four screws holding
back panel in place.
On the metal enclosure, remove the four front corner screws holding the display panel
in place. Remove rear cover. Disconnect the green earth (ground) cable; then feed wire
from sensors and power connection through seals to allow free movement of circuit
boards.
! CAUTION
The four screws are self-tapping and have a limited grip. Do not repeatedly remove
and tighten these screws.
3. Slide circuit assembly out to access the upper circuit board designated AS700EA.
Plastic enclosure slides out from the rear of its housing. Metal enclosure slides out
from the front of its housing.
4. Refer to Figure 21 to identify jumper locations.
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4. Configuration
5. Use Table 14 to locate appropriate jumper positions.
Table 14. Jumper Position for the Various Analog Outputs
Analog Output
J5
J6
J7
J10
4 - 20 mA
2 -3
2-3
2-3
2-3
0 - 20 mA
2-3
2-3
2-3
2-3
0 - 10 V dc
1-2
1-2
1-2
1-2
6. Move each jumper to its appropriate position.
7. Replace board assembly inside unit.
! CAUTION
On the plastic enclosure, a string must be rigged through the loop in the ribbon cable
such that when the board assembly is slid into the housing, the string/ribbon cable
may be pulled back simultaneously, thus preventing damage to the cable. See
Figure 21.
8. Replace cover. On metal enclosures, use Loctite (Part No. S0106ML) on the threads
of the front bezel screws, and Lubriplate (Part No. X0114AT) on the threads of the
rear cover screws.
9. An analog output calibration will now be necessary. Refer to “Analog Output
Calibration (LC01, HC01, LC02, HC02)” on page 59.
10. Make appropriate changes to the Analyzer identification label.
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4. Configuration
MI 611-168 – January 2021
Figure 21. Jumpers for Changing Analog Output
J10
J6
1
2
3
Output
J5
J6
J7
J10
4-20 mA 2-3 2-3 2-3 2-3
0-20 mA 2-3 2-3 2-3 2-3
0-10 Vdc 1-2 1-2 1-2 1-2
1
2
3
1
2
3
Output 1
1
2
3
J5 J7
Output 2
Analog Output Calibration (LC01, HC01, LC02, HC02)
This procedure is used to calibrate the Analog output. As this has been done at the factory,
recalibration should not be required unless the type of output has been changed. An ammeter or
voltmeter is required.
1. Connect an ammeter/voltmeter to the analog output terminals. See Figure 19 and
“Wiring of Plastic Enclosure” on page 24 or “Wiring of Metal Enclosure” on page 25.
2. Unlock the Analyzer using the security code.
3. Press Shift and while holding, press Setup. Release both keys.
4. Press Next several times until the code bL is displayed. Press Enter.
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4. Configuration
5. Use Next and Δ repeatedly until the personal security code is displayed (0800 from
the factory). Press Enter.
6. When display returns to bL, press Next until LC01 is displayed. Press Enter.
7. Calculate the low % input required by using the following formula:
Observed Reading – Desired Reading
Percent = ---------------------------------------------------------------------------------------------- × 100
Analog High
Example:
( 3.78 – 4.00mA )
------------------------------------------ × 100 = – 1.1Percent
20.00mA
8. Use Next and Δ repeatedly until the calculated value from Step 7 is displayed. Press
Enter.
NOTE
Iteration of the above procedure may be required. Repeat Steps 7 and 8 until
Observed Value is equal to the Desired Value.
NOTE
To make a minus sign appear on the display requires a digit other than zero to be
present on the display. Example: To make the display read -1.1%, first display 01.1%
and then change the first digit to a negative sign.
9. When the display returns to LC01, press Next once to display HC01. Press Enter.
10. Calculate the high % required using the following formula:
Observed Reading
Percent = ---------------------------------------------- × 100
Desired Reading
Example:
10.42V
------------------ × 100 = 104.2 Percent
10.00
11. Press Next and Δ repeatedly until the calculated value from Step 10 is displayed. Press
Enter.
NOTE
1. Repeat Steps 10 and 11 until Observed Value is equal to the Desired Value.
2. Procedure complete here for plastic enclosure.
12. For metal enclosure with a second output, move ammeter to second set of terminals.
Repeat Steps 3 through 5, then press Next once until LC02 is displayed. Press Enter.
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4. Configuration
MI 611-168 – January 2021
13. Calculate the low % input required by using the following formula:
Observed Reading - Desired Reading
Percent = --------------------------------------------------------------------------------------------- × 100
Analog High
Example:
( 3.78 – 4.00mA )
------------------------------------------ × 100 = – 1.1Percent
20.00mA
NOTE
To make a minus sign appear on the display requires a digit other than zero to be
present on the display. Example: To make the display read -1.1%, first display 01.1%,
then change the first digit to a negative sign.
14. Press Next and Δ repeatedly until the calculated value from Step 13 is displayed. Press
Enter.
NOTE
Iteration of the above procedure may be required. Repeat Steps 13 and 14 until
Observed Value is equal to Desired Value.
15. When the display returns to LC02, press Next once to display HC02. Press Enter.
16. Calculate the high % required using the following formula:
Observed Reading
Percent = ---------------------------------------------- × 100
Desired Reading
Example:
10.42V
------------------ × 100 = 104.2 Percent
10.00V
17. Use Next and Δ until the calculated value from Step 16 is displayed. Press Enter.
NOTE
Repeat Steps 16 and 17 until Observed Value is equal to the Desired Value.
18. Lock Analyzer using procedure in “Locking Analyzer Using Security Code” on
page 32.
This completes the Analog Output Calibration Procedure.
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4. Configuration
Figure 22. Output Terminals and Volt/Amm Meter (Plastic Enclosure Shown)
Volt or
Ammeter
TB2
1
TB3
M
+
M
2
3
-
3A
4
5
6
7
TB1
G L2/N L1/N
1
N
O
7
C
1
N
C
2
N
O
2
C
2
N
C
Changing the Security Code (LCC)
The following procedure is used to change the security code to another 4-digit code.
NOTE
If existing security code is forgotten, a new security code cannot be entered using this
procedure. In such a case, contact Global Customer Support.
1. Leave power on.
2. Press Lock. Display will show either Loc or Uloc.
3. If uLoc is displayed, proceed to Step 4.
4. If Loc is displayed, unlock the Analyzer using the procedure explained in “Unlocking
Analyzer Using Security Code” on page 32. Display will read uLoc.
5. Press Shift and while holding, press Setup. Release fingers from both keys.
6. Press Next several times until the code bL (Basic Setup Lock) is displayed. Press
Enter.
7. Then use Next and Δ repeatedly until existing security code is displayed (0800 from
factory).
8. Press Enter.
9. When display returns to bL, press Next several times until the code LCC (Lock Code
Change) is displayed.
10. Press Enter, then press the Next and increment (Δ) keys repeatedly until new desired
security code is displayed.
11. Press Enter. The new code will have to be used on all future entries.
12. Lock the Analyzer using the procedures explained in “Locking Analyzer Using
Security Code” on page 32.
62
5. Calibration
The Calibration section is divided into two parts.
“Electronic Bench Calibration” on page 63 contains the procedure for calibrating the 873RS
Analyzer with precision resistors and their theoretical values. In many cases this calibration
produces sufficient accuracy for the user application.
“Calibrating the Analyzer to a Specific Sensor” on page 69 provides additional calibration
procedures and standardization techniques. These additional procedures are recommended to
obtain the best system accuracy. These procedures MUST BE USED when additional extension
cables or junction boxes are used in installations.
! WARNING
On metal units, do not remove four front panel screws and remove electronics
package for calibration. The screws will not function properly with repeated use.
Electronic Bench Calibration
NOTE
Holding the Shift key between entries will prevent the Analyzer from timing out and
leaving the Setup entries.
This procedure is used to calibrate the 873 Analyzers with precision resistors and their theoretical
values. After this procedure is completed, the Cal Lo, Cal Hi, and Phase keys SHOULD NOT
BE TOUCHED.
NOTE
Invensys calibrates and configures all 873 Analyzers before leaving the factory with
resistors of 0.1% accuracy for the primaty measurements and 0.01% for the
temperature measurements. Calibration of this unit with resistors of less accuracy will
compromise the accuracy specifications of this unit. Calibration may be verified by
installing resistors on the unit.
! CAUTION
Do not press Enter if you are checking the calibration. It should not be necessary to
implement the Electronic Bench Calibration unless the FSC has been changed or
entered, or the Cal Hi and/or Cal Lo has been changed or entered.
Required:
Precision resistors corresponding to the High Cal value, a 100 KΩ or 110 Ω resistor for
temperature simulation, and a 0.001 μF polypropylene radial leaded film capacitor (Part No.
H0183TA) are required for this procedure.
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5. Calibration
Calibration Kit (Part No. BS805YZ included with each 873RS) contains parts necessary for
verifying calibration to the 20 MΩ •cm or 10 MΩ •cm ranges as well as the appropriate capacitor.
NOTE
1. Do not use a resistance decade box for the electronic bench calibration; the cable
connection will add “quadrature” during the calibration, which will result in
erroneous resistivity values.
2. The resistors included in this kit are only 0.1% resistors, which will allow you to
verify the calibration of an 873RS Analyzer. However, using 0.1% resistors to
calibrate this instrument will reduce the accuracy specification on this instrument.
If you need to perform a more precise calibration, it is recommended that you
purchase the specified precision (0.01%) resistors.
Procedure:
Calibration of Cell 1 Channel:
1. Disconnect all sensor leads from terminal strip TB2.
2. Unlock Analyzer (see “Unlocking Analyzer Using Security Code” on page 32).
3. Check and adjust the Cell code of the unit. Refer to “CELL Display and Output
Configuration (CELL)” on page 33. Set this code so the first digit is 1: “1XXX”.
4. Check and adjust the Cd code of the unit. Refer to “Compensation and Damping
(Cd)” on page 36. Set this code to read “0000”. The unit should have no damping
and should utilize absolute temperature compensation.
5. Reset the Full Scale value of the Analyzer. Refer to “Changing the Full Scale Range
(FSC)” on page 50. Even if the existing Full Scale value is the desired value, it is
important to reenter the same value. When the FSC value is entered, Error Code
“ER4” should begin to flash on the display.
NOTE
1. If an Error Code of higher priority is present, it will preempt the ER4 message.
2. Holding the Shift key between entries will prevent the Analyzer from timing out
and leaving the Setup entries.
6. Reset CF1 to .1000 (the theoretical cell factor). Press Enter. See “Calibrating the
Analyzer to a Specific Sensor” on page 69.
7. Reset tCF1 to 25.00 (the theoretical temperature transducer value). Press Enter. See
“Calibrating the Analyzer to a Specific Sensor” on page 69.
8. Checking the Temperature Circuit Calibration
a. Determine which type temperature compensation your Analyzer has by checking
the CONFIGURATION CD entry on the model identification label affixed to
the Analyzer (see Figure 4).
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5. Calibration
MI 611-168 – January 2021
NOTE
The 871CC Sensor types A through F use a 100 kΩ thermistor for automatic
temperature compensation. The 871CC Sensors K through M use a 100 Ω RTD for
automatic temperature compensation and are recommended for all measurements at
elevated temperatures.
Connect a 110 Ω or a 100 kΩ resistor as applicable across terminals 3 and 3A on
terminal TB2. Refer to Figure 23.
Figure 23. Temperature Simulation (NEMA 4X Enclosure Shown)
100 kΩ Resistors
1 2 3
3A 4 5
6 7
2- 2+ 1- 1+
TB4
TB2
TB1
TB3
NC C NO NC C NO
LO
HI
b. Press Temp. The unit should be in the Automatic Temperature mode; no decimal
should be visible after the “C” or “F” legend. If there is a decimal after the “C” or
“F” legend, it should be removed. Press the increment key (Δ) once after pressing
Temp; then press Enter. This removes the decimal.
c. Press Temp. The display should read approximately “25.C” or “77.F”. If the
display does not read these values, verify that the correct resistor is being used, and
ensure that it is installed correctly. If these measures do not improve the value, see
“Changing the Temperature Circuitry” on page 51 for recalibrating procedures.
9. Zero and Span Calibration
a. Produce a short across terminals 1 and 2 on terminal TB2. This may be
accomplished by attaching a short wire between contacts 1 and 2.
b. Wait at least 15 seconds for the electronics to stabilize.
c. Press Shift and while holding, press Cal Lo. Use Next and Δ repeatedly until
the display reads 0.00. Press Enter. Remove the shorting wire.
d. Calculate the Resistance Input required for Calibrate High Value. The Cal Hi
value should fall within the range of the FSC that has been chosen.
Resistance Input = Cell Factor x Cal Hi Value
(in M •Ω)
(0.100 cm-1) (M Ω •cm)
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5. Calibration
Example:
For a resistivity display of 20.00 MΩ •cm,
Resistance Input = (0.1000)(20) = 2.000 M•Ω
Other sample resistance inputs:
For a display of 18.00 M Ω•cm,
Resistance Input = 1.800 MΩ
For a display of 10.00 M Ω•cm,
Resistance Input = 1.000 M Ω
For a display of 2.000 M Ω•cm,
Resistance Input = .2000 M•Ω
e. Connect resistor corresponding to calculated Cal Hi Value between terminals 1
and 2 of TB2 (see Figure 24).
f. Wait at least 15 seconds for the electronics to stabilize.
g. Press Shift and while holding, press Cal Hi. Press Next and Δ repeatedly until
the display reads desired Cal Hi value. Press Enter. Leave the resistor across the
terminals. The Er 4 flag will continue to flash.
10. The Phase Calibration
This part of the Bench Calibration procedure adjusts the Analyzer for changes in capacitance
that may be introduced by the cable or sensor.
a. Connect a .001 μF polypropylene capacitor across terminals 1 and 2 of TB2
leaving the resistor connected from the previous step (in parallel with the resistor).
Refer to Figure 24.
b. Wait at least 15 seconds for the electronics to stabilize.
c. Press Shift and while holding, press Phase. Display will read Cal Hi setting.
Press Enter. The ER4 code should stop flashing.
d. Remove capacitor from terminals 1 and 2 of TB2. Leave resistor connected. Wait
at least 15 seconds.
e. Press Shift and while holding, press Cal Hi. Use Next and Δ repeatedly until
the display reads desired Cal Hi value. Press Enter.
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5. Calibration
MI 611-168 – January 2021
Figure 24. Bench Calibration (NEMA 4X Enclosure Shown)
1 2 3
3A 4 5
6 7
2- 2+ 1- 1+
TB4
TB2
TB1
TB3
NC C NO NC C NO
LO
HI
Calibration of Cell 2 Channel
11. Check and adjust the Cell code of the unit so that Cell 2 is displayed. Refer to “CELL
Display and Output Configuration (CELL)” on page 33. Set this code so the first
digit is 2: “2XXX”.
12. Reset CF2 to .1000 (the theoretical cell factor). Press Enter. See “Calibrating the
Analyzer to a Specific Sensor” on page 69.
13. Reset tCF2 to 25.00 (the theoretical temperature transducer value). Press Enter. See
“Calibrating the Analyzer to a Specific Sensor” on page 69.
14. The Temperature Circuit calibration must first be checked.
a. Determine which type temperature compensation your Analyzer is set up for by
checking the CONFIGURATION CD entry on the model identification label
affixed to the Analyzer. See Figure 4.
NOTE
The 871CC Sensor types A through F use a 100 kΩ thermistor for automatic
temperature compensation. The 871CC Sensors K through M use a 100 Ω RTD for
automatic temperature compensation and are recommended for all measurements at
elevated temperatures.
Connect a 110 Ω or 100 kΩ resistor as applicable across terminals 4 and 5 on
terminal strip TB2. Refer to Figure 23.
b. Press Temp. The unit should be in the Automatic Temperature mode; no decimal
should be visible after the “C” or “F” legend. If there is a decimal after the “C” or
“F” legend, it should be removed. Press Δ once after pressing Temp; then press
Enter. This removes the decimal.
c. Press Temp. The display should read approximately “25.C” or “77.F”. If the
display does not read these values, verify that the correct resistor is being used and
ensure that it is installed correctly. If the response is not improved by these
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5. Calibration
measures, go to “Changing the Temperature Circuitry” on page 51 for
recalibration.
15. Zero and Span Calibration
a. Produce a short across terminals 6 and 7 of terminal strip TB2.
b. Wait at least 15 seconds for the electronics to stabilize.
c. Press Shift and while holding, press Cal Lo. Use Next and Δ repeatedly until
the display reads 0.00. Press Enter. Remove shorting wire.
d. Calculate the Resistance Input required for Calibrate High Value. The Cal Hi
value should fall within the range of the FSC that has been chosen.
Resistance Input = Cell Factor x Cal Hi Value
(in MΩ)
(0.1000 cm-1) (MΩ•cm)
Example:
For a resistivity display of 20.00 MΩ•cm,
Resistance Input = (0.1000)(20) = 2.000 MΩ
(Calibration Kit contains 2.00 MΩ resistor)
Other sample resistance inputs:
For a display of 18.00 MΩ•cm,
Resistance Input = 1.800 MΩ
For a display of 10.00 MΩ•cm,
Resistance Input = 1.000 MΩ
For a display of 2.000 MΩ•cm,
Resistance Input = .2000 MΩ
e. Connect resistor corresponding to calculated value between terminals 6 and 7 of
TB2. See Figure 24.
f. Wait at least 15 seconds for the electronics to stabilize.
g. Press Shift and while holding, press Cal Hi. Use Next and Δ repeatedly until
the display reads desired Cal Hi value. Press Enter. Leave the resistor across the
terminals.
16. The Phase Calibration
This part of the Bench Calibration procedure adjusts the Analyzer for changes in
capacitance that may be introduced by the cable or sensor.
a. Connect a .001 μF polycarbonate capacitor across terminals 6 and 7 of TB2
leaving the resistor connected from the previous step (in parallel with the resistor).
Refer to Figure 24.
b. Wait at least 15 seconds for the electronics to stabilize.
c. Press Shift and while holding, press Phase. Display will read Cal Hi setting.
Press Enter. The ER4 code should stop flashing.
68
5. Calibration
MI 611-168 – January 2021
d. Remove capacitor from terminals 6 and 7 of TB2. Leave resistor connected. Wait
at least 15 seconds.
e. Press Shift and while holding, press Cal Hi. Press Next and Δ repeatedly until
the display reads desired Cal Hi value. Press Enter.
17. Disconnect resistors from terminal strip TB2.
18. Reconnect all sensor leads to terminal strip TB2.
19. Press Temp. The unit should be in the automatic temperature compensation mode (no
decimal after the legend). If it is not, press Δ either once (Fahrenheit) or three times
(Centigrade) to remove the decimal point after the F or C legend. Press Enter.
20. Check and adjust the Cd code of the unit to the desired values. For temperature
compensation of ultrapure water, the fourth digit of this code must be a 1;X001. Refer
to “Compensation and Damping (Cd)” on page 36.
Check and adjust the CELL code of the unit to the desired values (“CELL Display
and Output Configuration (CELL)” on page 33).
21. Lock Analyzer (see “Locking Analyzer Using Security Code” on page 32).
This completes the Electronic Bench Calibration.
Calibrating the Analyzer to a Specific Sensor
Temperature Cell Factor (tCF1 and tCF2) and Cell Factor
(CF1 and CF2) Adjustments
Foxboro resistivity sensors are manufactured under strict guidelines for quality and uniformity.
Even with the stringent specifications of our assembly procedures, small offsets from theoretical
values are possible. Under many circumstances, the theoretical bench calibration and a sensor can
still provide sufficient information to the user. In these cases, the sensor should be connected to
the Analyzer and used without further calibration.
NOTE
For the best possible system accuracy of an 873RS and 871CC sensor, additional
calibrations are required to standardize these small offsets.
An accurate temperature signal is required for proper pure water temperature compensation,
especially when measuring over a large temperature gradient. The temperature cell factors (tCF1
and tCF2) are used to offset a small deviation from ideal for the two sensors. If patch cables are
used, a new tCF must be determined and input. At 25.0°C, a 0.1°C error in temperature can
result in a resistivity error of 1.1%.
NOTE
The 871CC Sensor type A through F use a 100 kΩ thermistor for automatic
temperature compensation. The 871CC Sensors K through M use a 100 Ω RTD for
automatic temperature compensation and are recommended for all measurements at
elevated temperature.
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MI 611-168 – January 2021
5. Calibration
Additionally, individual sensor cell factors may differ slightly from .1000 cm-1 (their nominal
constant). The cell factors (CF1 and CF2) are used to offset these small deviations from ideality
for the two sensors.
871CC Sensors are stamped with a 4-digit number (such as .1001) which is the cell factor (CF) of
that particular cell when tested in our factory. These cells are also stamped with a temperature
value (tCF) (such as 24.97°C) which is the temperature where that particular transducer read its
theoretical resistance value. See Figure 25. When the sensor is connected directly to the Analyzer,
these cell factors may be input directly into the 873RS to correct for these offsets. Alternately, the
procedures that follow may be used to determine these offset values, and must be used when
additional cable lengths or junction boxes are used with the sensors.
Determining tCF
1. Place 871CC sensor and an accurate Centigrade thermometer (with .10°C resolution)
into a container of water. Allow the system to reach thermal equilibrium.
2. Press Temp. Put the Analyzer into Automatic Temperature Compensation, no decimal
after the C. If there is a decimal after the C, it may be removed. Press Δ once after
pressing Temp; then press Enter.
Figure 25. Sensor Identification
871CC-A2
0.1
2B0530
3. Read the temperature displayed on the 873 to the hundredths place. When Temp is
pressed, the current temperature value with tenths place will alternate with the C
legend. The value read by the 873 must now be viewed to the hundredths place. Press
Temp followed by Next five times. Only three numbers may be viewed on the display,
and the first digit will not be visible (e.g., 25.20 will be displayed as 5.20).
4. Determine the difference in values between the two temperature devices; e.g., the
thermometer reads 24.70°C, and the 873 says (2)5.20 C; the 873 is reading higher by
.50°C.
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5. Calibration
MI 611-168 – January 2021
5. Subtract this value from 25.00 (e.g., 25.00 – .50 = 24.50). This is your new TCF
value.
NOTE
If the 873 value is less than the thermometer, the difference should be added to 25.00.
Entering a tCF Value
NOTE
1. Before this procedure is performed, verify that the 873RS Analyzer has been
electronically bench-calibrated. Electronic bench calibration is performed at the
factory on all new Analyzers.
2. After performing the procedure given below, the use of keys Cal Hi and Cal Lo is
not feasible. The procedure given in the “Electronic Bench Calibration” on
page 63 must precede, not follow, the procedure below.
1. Unlock Analyzer (see “Unlocking Analyzer Using “Unlocking Analyzer Using Security
Code” on page 32).
2. Press Shift and while holding, press Setup. Release fingers from both keys.
3. Press Next several times until the code bL (Basic Setup Lock) is displayed.
4. Press Enter and then use Next and Δ repeatedly until personal security code is
displayed (0800 from factory).
5. Press Enter.
6. When display returns to bL, press Next several times until the entry tCF1 or tCF2
(depending upon the cell value you are entering) is displayed.
7. Press Enter and then use Next and Δ repeatedly until desired value (matching the
data on the cell) is displayed.
8. Press Enter.
9. Recheck any differences that exist between a thermometer and temperature displayed
on the 873.
10. Lock Analyzer using procedure in “Locking Analyzer Using Security Code” on
page 32.
Determining (or Verifying) a CF
NOTE
1. The following procedure is used to determine or verify a CF value. To avoid
contaminating the cell, sensors should be handled by the cable end only.
2. Sensors should not be placed into solutions containing oils or chemicals that could
coat the cells and change the cell factor.
3. Resistivity standard solutions are not commercially available. A known solution
resistivity or a “Standard” cell, an 871CC sensor whose cell factor (CF) is known, is
required with this procedure.
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MI 611-168 – January 2021
5. Calibration
1. Install sensor into a flowing clean water loop whose resistivity is known or along with
an 871CC sensor whose cell factor is known.
2. Allow sensor to reach steady state equilibrium. Allow one hour or more for this to
occur; the values displayed on the Analyzer should stop changing. The cell actually
will be “cleaning” itself off during this time.
3. If two sensors are being compared, verify that their temperatures are in agreement.
4. Adjust the Cd code of the 873 to 0000 to read absolute conductivity. Refer
to “Compensation and Damping (Cd)” on page 36.
5. Adjust and enter the CF code for the sensor whose value is known. See “Entering a CF
Value” on page 73.
6. Adjust and enter CF code .1000 for sensor whose CF is to be determined.
7. Read the apparent resistivity displayed for the sensor whose CF is being determined.
Read the resistivity displayed for the solution that is known.
8. Using either equation below, calculate the cell factor for the sensor being tested:
Resistivity from Cell CF unknown x .100 = CELL FACTOR
------------------------------------------------------------------------------------------------------Resistivity from Cell CF known
or
Resistivity from Cell CF unknown x .100 = CELL FACTOR
------------------------------------------------------------------------------------------------------Known Solution Resistivity
Example 1:
The solution resistivity is known to be 10.12 MΩ •cm. The sensor being tested reads
10.15 MΩ •cm.
× .1
CF = 10.15
------------------------- = .1003
10.12
Example 2:
The solution resistivity is found to be 18.05 MΩ •cm. The sensor whose CF is being determined
reads 17.89 MΩ⋅cm.
9. Enter the new CF value (“Entering a CF Value” on page 73).
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5. Calibration
MI 611-168 – January 2021
× .1
CF = 17.89
------------------------- = .0991
18.05
10. Adjust the Cd code of the 873 to X001 if temperature compensation for pure water is
desired. Refer to “Compensation and Damping (Cd)” on page 36. The unit may have
damping input by this code also.
Entering a CF Value
NOTE
1. This procedure should be implemented after the 873RS Analyzer has been
electronically bench calibrated. The theoretical value of .1000 cm-1 is input to the
Analyzer at the factory on all new Analyzers.
2. After performing the procedure given below, the use of keys Cal Hi and Cal Lo is
not feasible. The procedure given in “Electronic Bench Calibration” on page 63
must precede, not follow, the procedure below.
1. Unlock Analyzer (see “Unlocking Analyzer Using Security Code” on page 32).
2. Press Shift and while holding, press Setup. Release fingers from both keys.
3. Press Next several times until the code bL (Basic Setup Lock) is displayed.
4. Press Enter and then press Next and Δ repeatedly until personal security code is
displayed (0800 from factory).
5. Press Enter.
6. When display returns to bL, press Next several times until the entry CF1 or CF2
(depending on the cell you wish to "fine tune") is displayed.
7. Press Enter, then press Next and Δ repeatedly until desired value (matching the data
on the cell) is displayed.
8. Press Enter.
9. Recheck any differences that exist between sensors on the 873 using the technique
described previously.
10. Lock Analyzer (see “Locking Analyzer Using Security Code” on page 32).
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MI 611-168 – January 2021
74
5. Calibration
6. Diagnostics
Troubleshooting
Table 15. Troubleshooting Symptoms
Symptom
Approach
Noisy Signal
May be flow related.
1. Check Analyzer noise by simulating sensor signal
with a resistor.
2. Increase damping.
3. Reorient sensor.
Resistivity Increases
Gas bubbles may be trapped.
Resistivity Reads Incorrectly
Temperature Reads Incorrectly
1. Check to see if correct TCF is being used. Extension
cables and junction box use will require a new TCF be
determined.
2. Verify 873 is set up for proper temperature transducer. See
“Electronic Bench Calibration” on page 63, Items 8 and 14.
Accuracy
1. Accuracy of the sensor may be affected by deposits from
the process liquid. Consult sensor MI for cleaning
recommendations.
Error Codes
When the Analyzer is operating normally, the measurement value is displayed constantly. If error
or alarm conditions exist, the display alternates between the measurement value and the
error/alarm message at a one second rate. The alternate (error/alarm) messages are shown in
Table 16.
Table 16. Error/Alarm Messages
Alternate
Display
Condition
Priority
Er 1
Instrument Fault, RAM/ROM,
software watchdog timer
1
(Highest)
Er 2
User-defined temperature range
3
error or temperature measurement
error
Analyzer set up for wrong
temperature transducer
Action Required to Clear Message
Reenter security code in LCC code twice.
See “Changing the Security Code (LCC)” on
page 62.
Power down unit.
Change user-defined temperature limits. UtL or LtL.
Replace sensor.
Place temperature in manual mode (e.g., 25°C).
See “Changing the Temperature Circuitry” on
page 51.
Er 3
User-defined measurement range
error
4
Change user-defined measurement limits, UL or LL.
Replace sensor.
Er 4
Measurement calibration incorrect 2
Recalibrate Analyzer using Bench Calibration procedure.
A Hi
Measurement in H alarm
H Alm state, timers on, or in deadband.
6
A HH
Measurement in HiHi alarm
5
Both Alarms configured as High Alarms.
A LO
Measurement in L alarm
8
L Alm state, timers on, or in deadband.
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MI 611-168 – January 2021
6. Diagnostics
Table 16. Error/Alarm Messages (Continued)
Alternate
Display
Condition
Priority
A LL
Measurement in LoLo alarm
****
Measurement over or under range 9
of analog output limits
Err
Incorrect code or parameter
attempted
NOTE
7
2
Action Required to Clear Message
Measurements must remain within HO1 and LO1 (HO2
or LO2) limits configured.
Check code and reenter.
If two or more errors exist simultaneously, the Analyzer will flash only the error with
the highest priority. If the highest priority error is cleared and a lower priority error
still remains, the Analyzer will then flash the highest priority error of the remaining
errors.
76
6. Diagnostics
MI 611-168 – January 2021
Detachable Configuration Field Sheet
Table 17. Configuration Setup Entries
Displayed
Symbol
Parameters and Values
Accessed
User Settings
Displayed
Symbol
Parameters and Values
Accessed
CELL
Configuration of Display and
Analog Outputs
LAtt
Low Alarm Trigger Time
Hold
Hold and sets the Analog
output value in Hold
LAFt
Low Alarm Feed Time
Cd
Temperature Compensation
and Damping
Damping Factor
Temperature
Compensation
LAdL
Low Alarm Delay Time
HAC
H Alarm Configuration
Measurement Selection
Low/High/Instrument plus
Passive/Active State
% Hysteresis
UL
User-Defined Upper
Measurement Limit - Both
Cells
HAtt
High Alarm Trigger Time
LL
User-Defined Lower
Measurement Limit - Both
Cells
HAFt
High Alarm Feed Time
UtL
User-Defined Upper
Temperature Limit - Both Cells
HAdL
High Alarm Delay Time
LtL
User-Defined Lower
Temperature Limit - Both Cells
LAC
L Alarm Configuration
Measurement Selection
Low/High/Instrument plus
Passive/Active State
% Hysteresis
HO1
100% Analog Output Channel 1
HO2
100% Analog Output Channel 2
LO1
0% Analog Output - Channel 1
LO2
0% Analog Output - Channel
2
User Settings
Table 18. Hold Code—Hold Analog Output Values
Digit 1
Digits 2, 3, and 4
0 = No Hold
Hold ON, Analog Output on Hold
1 - Alarms held in present state
2 - Alarms held in off state
3 - Alarms held in on state
000 to 100% of Analog Output Range
Table 19. Basic Setup Entry Selection
Symbol
Parameter and Value Accessed
bL
Basic Setup Lock Control
FSC
Full Scale Value
CF 1
Cell Factor - Cell 1
tCF 1
Temperature Cell Factor - Cell 1
User Settings
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MI 611-168 – January 2021
6. Diagnostics
Table 19. Basic Setup Entry Selection (Continued)
Symbol
Parameter and Value Accessed
User Settings
tEC 1
Thermistor Temperature Electronics Calibration Cell 1
tCL 1
RTD Low Temperature Electronics Calibration Cell 1
tCC 1
RTD Mid Temperature Electronics Calibration Cell 1
tCH 1
RTD High Temperature Electronics Calibration Cell 1
LCC
Lock Code Change
CF 2
Cell Factor - Cell 2
tCF 2
Temperature Cell Factor - Cell 2
tEC 2
Temperature Channel Electronics Calibration Cell 2
tCL 2
RTD Low Temperature Electronics Calibration Cell 2
tCC 2
RTD Mid Temperature Electronics Calibration Cell 2
tCH 2
RTD High Temperature Electronics Calibration Cell 2
LCCO1
Analog Out 1 Electronics Lower Calibration
HCO1
Analog Out 1 Electronics Upper Calibration
LCO2
Analog Out 2 Electronics Lower Calibration
HCO2
Analog Out 2 Electronics Upper Calibration
SFt
Software Version Number
SOH
Sales Order High
SOL
Sales Order Low
Table 20. CELL Code—Display and Output Configuration
Digit 1
Digit 2
Digit 3
Digit 4
Measurement And Display
Not Used
Output 1
Output 2
1 - Measures and displays Cell 1 only
2 - Measures and displays Cell 2 only
3 - Measures Cell 1 and Cell 2
Displays Cell 1
4 - Measures Cell 1 and Cell 2
Displays Cell 2
7 - Ratio
8 - % Rejection
Digit 2 is not used 1 - Resist. Cell 1
and should be set 2 - Resist. Cell 2
at 0.
3 - Temp Cell 1
4 - Temp Cell 2
5 - Log (resist. Cel1)
6 - Log (resis. Cel2)
7 - Ratio
8 - % Rejection
1 - Resist. Cell 1
2 - Resist. Cell 2
3 - Temp Cell 1
4 - Temp Cell 2
5 - Log (resist. Cel1)
6 - Log (resis. Cel2)
7 - Ratio
8 - % Rejection
Table 21. Cd Code—Compensation and Damping
Digit 1
Digit 2
Digit 3
Digit 4
Damping
Not Used
Not Used
Temperature Compensation
0 = none
1 = 10 second
2 = 20 second
3 = 40 second
UL
LL
UtL
LtL
78
=
=
=
=
ENTER 0
ENTER 0
0 = Absolute (no compensation)
1 = Ultrapure water temperature correction
applied M W Þcm resistivity is referenced
to 25° C
The Upper Limit is 999.9 ΜΩ•cm.H01 = May be set to any value between -0.99 and 99.99.
The Lower Limit is -.999 MΩ•cm.L01 = May be set to any value between -0.99 and 99.99.
The Upper Limit is 200°C.H02 = May be set to any value between -0.99 and 99.99.
The Lower Limit is -20°C (-5°F).L02 = May be set to any value between -0.99 and 99.99
6. Diagnostics
MI 611-168 – January 2021
Table 22. HAC and LAC Codes—Alarm Configuration
Digit 1
Digit 2
Digits 3 & 4
Alarm Selection
Configuration
Hysteresis
1 - Meas Cell 1
2 - Meas Cell 2
3 - Temp Cell 1
4 - Temp Cell 2
7 - % Ratio
8 - % Rejection
1 - Low/Passive
2 - Low/Active
3 - High/Passive
4 - High/Active
5 - Instrument/Passive
6 - Instrument/Active
7 - Hold/Passive
8 - Hold/Active
00 to 99% of Full Scale
Table 23. HAFt, HAdL, LAFt, and LAdL Time Codes
Digits 1 and 2
00 to 99 minutes
Digit 3
Digit 4
0 to 9 tenths of minutes
0 to 9 hundredths of minutes
.
Table 24. Troubleshooting Symptoms
Symptom
Approach
Noisy Signal
May be flow related
1. Check Analyzer noise by simulating sensor signal with a resistor.
2. Increase damping.
3. Reorient sensor.
Resistivity Increases
Gas bubbles may be trapped.
Resistivity Reads
Incorrectly
Temperature Reads
Incorrectly
1.
Accuracy
Accuracy of the sensor may be affected by deposits from the process liquid. Consult sensor
MI for cleaning recommendations.
2.
Check to see if correct TCF is being used. Extension cables and junction box use will
require a new TCF be determined.
Verify 873 is set up for proper temperature transducer. See
“Electronic Bench Calibration” on page 63, Items 8 and 14.
Table 25. Error/Alarm Messages
Alternate
Display
Condition
Priority
Action Required to Clear Message
Er 1
Instrument Fault, RAM/ROM, software 1
1.
watchdog timer
(Highest)
2.
Reenter security code in LCC code twice.
See “Changing the Security Code (LCC)” on page 62.
Power down unit.
Er 2
User-defined temperature range error 3
or temperature measurement error
Change user-defined temperature
limits. UtL or LtL.
Replace sensor.
Place temperature in manual mode
(e.g., 25°C.)
See “Changing the Temperature Circuitry” on page 51.
1.
2.
3.
Analyzer set up for wrong temperature
transducer.
4.
Er 3
User-defined measurement range
error
4
1.
Er 4
Measurement calibration incorrect
2
Recalibrate Analyzer using Bench Calibration procedure.
A Hi
Measurement in Hi alarm
6
H Alm state, timers on, or in deadband.
2.
Change user-defined measurement
limits, UL or LL.
Replace sensor.
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MI 611-168 – January 2021
6. Diagnostics
Table 25. Error/Alarm Messages (Continued)
Alternate
Display
Condition
Priority
5
Action Required to Clear Message
A HH
Measurement in HiHi alarm
Both Alarms configured as High Alarms.
A LO
Measurement in Lo alarm
8
L Alm state, timers on, or in deadband.
A LL
Measurement in LoLo alarm
7
Measurements must remain within HO1 and LO1 (HO2 or
LO2) limits configured.
****
Measurement over or under range of
analog output limits
9
H Alm state, timers on, or in deadband.
Err
Incorrect code or parameter attempted 2
Check code and reenter.
NOTE:If two or more errors exist simultaneously, the Analyzer will flash only the error with the highest priority. If the highest
priority error is cleared and a lower priority error still remains, the Analyzer will then flash the highest priority error of the
remaining errors.
For Warranty Information 1-866-746-6477
For Electrochemistry Analyzer Repair/Troubleshooting Information
508-549-2168
For Electrochemistry Technical Assistance and Application Support
508-549-4730
Or by FAX
80
508-549-4734
7. User Notes
Single Sensor Use
This section allows fault-free setup of the 873RS for single sensor use. Because two sensor inputs
are available on the 873 Analyzer, proper configuration is required to prevent errors from flagging.
After wiring up the sensor, follow the steps below to determine the 5 pertinent configuration code
assignments. Error codes will occur if the unit is configured improperly.
For Cell 1 Configuration
1. Wire Sensor to TB2.
Cell 1 terminals 1, 2, 3, 3A
2. Choose Cell Code.
Digit
1
1
2
0
Not Used
3
1
or
3
or
5
4
1
or
3
or
5
3. Will you be using Analog output(s)?
If Yes, set to desired values.
See “Output #1's 100% Analog Value (HO1)” on page 48 and “Output #1's 0%
Analog Value (LO1)” on page 48.
If No, set to:
HO1 = 99.99 and LO 1 = -.99
4. Will you be using Alarms?
LAC
Digit
1
2
3
4
1
or
3
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MI 611-168 – January 2021
7. User Notes
HAC
Digit
1
2
3
4
3
4
1
or
3
If Yes, set digits 2, 3, and 4 as desired.
If No, set LAC = 1100
set HAC = 1300
set L ALM = - .99
set H ALM=99.99
For Cell 2 Configuration
1. Wire Sensor to TB2.
Cell 2 terminals 4, 5, 6, 7
2. Choose Cell Code.
Digit
1
2
2
0
Not Used
2
or
4
or
6
2
or
4
or
6
If Yes, set to desired values. See “Output #2's 100% Analog Value (H02)” on page 48
and “Output #2's 0% Analog Value (L02)” on page 49.
If No, set to:
HO2 = 99.99 and LO2 = -.99
3. Will you be using Alarms?
LAC
Digit
1
2
or
4
82
2
3
4
X
X
X
X
X
X
7. User Notes
MI 611-168 – January 2021
HAC
Digit
1
2
or
4
2
3
4
X
S
X
X
X
X
If Yes, set digits 2, 3, and 4 as desired.
If No, set LAC = 2100
set HAC = 2300
set L ALM = - .99
set H ALM=99.99
Dual Sensor Use
Ratio:
For Ratio measurements, the sensor designated Cell 1 must be located physically on the untreated
water source. Cell 2 is placed after the “clean up” operation.
Cell Code
Digit
1
7
2
0
Not Used
3
X
4
X
Where XX means any values.
Set digits 3 and 4 as desired. If the Analog outputs will be used, set H01, L01 and H02, L02 to
the proper values. If an output will not be used (or NEMA 1 version), set to:
H01 and H02 = 99.99; L01 and L02 = -.99.
Percent Rejection:
For Percent Rejection measurements, the sensor designated Cell 1 must be located physically on
the untreated water source. Cell 2 is placed after the “clean up” operation.
Cell Code
Digit
1
8
2
0
3
X
4
X
Where XX means any values.
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MI 611-168 – January 2021
7. User Notes
Set digits 3 and 4 as desired. If the Analog outputs will be used, set H01, L01 and H02, L02 to
the proper values. If an output will not be used (or NEMA 1 version), set to:
H01 and H02 = 99.99; L01 and L02 = -.99.
Redundant Sensor Operation
In extremely critical processes where an error in measurement could cause serious effects, two
sensors can be used as a check of measurement. Cell 1 will be designated the primary cell from
which measurement is taken. The cell code should be set.
Cell Code
Digit
1
3
2
0
Not Used
3
X
4
X
Where XX means any values.
Set the analog outputs as desired (digits 3 and 4 of cell code) to functions of Cell 1's operation.
H01 and L01, H02 and L02 should be set appropriately.
Configure the alarms, HAC and LAC to Ratio measurement.
LAC
Digit
1
7
2
X
3
X
4
X
HAC
Digit
1
7
2
X
3
X
4
X
Determine acceptable variances between the two sensors at the control before alarming. Calculate
the ratio relationship:
Cell 1
--------------- × 100
Cell 2
Set L ALM and H ALM and wire Alarm terminals to appropriate Alarm device.
84
7. User Notes
MI 611-168 – January 2021
Backup Sensor Operation
In certain applications, a second or backup sensor is installed but is not configured. In cases where
the primary sensor indication is suspect, the second already installed sensor is simply configured
into duty.
For Cell 1 Configuration
1. Wire Sensor to TB2.
Cell 1 terminals 1, 2, 3, 3A
2. Choose Cell Code.
Digit
1
3
2
3
0
Not Used
4
1
or
3
or
5
1
or
3
or
5
3. Will you be using Analog output(s)?
If Yes, set to desired values.
See “Output #1's 100% Analog Value (HO1)” on page 48 and “Output #1's 0%
Analog Value (LO1)” on page 48.
If No, set to:
HO1 = 99.99 and LO 1 = -.99
4. Will you be using Alarms?
LAC
Digit
1
2
3
4
3
4
1 or 3
HAC
Digit
1
2
1 or 3
If Yes, set digits 2, 3, and 4 as desired.
If No, set LAC = 1100
set HAC = 1300
set L ALM = - .99
set H ALM=99.99
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MI 611-168 – January 2021
7. User Notes
For Cell 2 Configuration
1. Wire Sensor to TB2.
Cell 2 terminals 4, 5, 6, 7
2. Choose Cell Code.
Digit
1
4
2
3
0
Not Used
4
2
or
4
or
6
2
or
4
or
6
If Yes, set to desired values.
See “Output #2's 100% Analog Value (H02)” on page 48 and “Output #2's 0%
Analog Value (L02)” on page 49.
If No, set to:
HO2 = 99.99 and LO2 = -.99
3. Will you be using Alarms?
LAC
Digit
1
2
or
4
2
3
4
X
X
X
X
X
X
HAC
Digit
1
2
or
4
2
4
X
S
X
X
X
X
If Yes, set digits 2, 3, and 4 as desired.
If No, set LAC = 2100
set HAC = 2300
set L ALM = - .99
set H ALM=99.99
86
3
8. Alarm Contact Maintenance
The alarm relay contacts are selected to switch loads equal to or greater than 20 watts. The
minimum contact current is 1 ampere. The silver alloy contacts rely on the very slight arc
generated during switching to eliminate oxide layers that form on the contacts. When the
contacts are used at low (signal) levels, contact function may become unreliable over time due to
the formation of an oxide layer on the contacts.
When contacts must be used at low levels, attention must be paid to contact condition. The
maximum contact resistance for new relays is 100 milliohms. Values above this level or unstable
values indicate deterioration of the contact surface as noted above and may result in unreliable
alarm function.
The contact surfaces can be restored as follows:
1. Disconnect the alarm wiring from the analyzer.
2. Connect a load of 20 W or more as shown in Figure 26 so that both NO and NC
contacts are exercised.
3. Use the analyzer to switch the alarm relay several times.
4. Disconnect the load installed in Step 2 and reconnect the wiring removed in Step 1.
5. Check to ensure that the alarms are functioning properly.
Figure 26. Alarm Contact Reconditioning Circuit
NO
C
20 W LOAD
120 V ac SUPPLY
NC
87
MI 611-168 – January 2021
88
8. Alarm Contact Maintenance
9. Warranty
Thank you for buying a Foxboro 873RS electrochemical analyzer. We also supply pH/ORP,
contacting conductivity, and electrodeless conductivity analyzers and equipment. Contact us for
your analysis needs.
For sales information or to place an order, contact your local Invensys distributor or local Invensys
sales office.
For Warranty Information 1-866-746-6477
For Electrochemistry Analyzer Repair/Troubleshooting Information
508-549-2168
For Electrochemistry Technical Assistance and Application Support 508-549-4730
Or by FAX
508-549-4734
WARRANTY
Invensys expressly warrants the products manufactured by it as meeting the applicable Invensys product
specifications. INVENSYS MAKES NO OTHER WARRANTIES EITHER EXPRESS OR IMPLIED
(INCLUDING WITHOUT LIMITATION WARRANTIES AS TO MERCHANTABILITY OR FITNESS FOR A
PARTICULAR PURPOSE). Purchaser retains responsibility for the application and functional adequacy of the
offering. In addition, the following shall constitute the exclusive remedies for any breach by Invensys of its
warranties hereunder.
MATERIAL, WORKMANSHIP, AND TITLE: Invensys warrants to Purchaser that all products manufactured by
Invensys shall be free from defects in material, workmanship, and title, and agrees to either replace, or repair
free of charge, any such product, component, or part thereof which shall be returned to the nearest
authorized Invensys repair facility within one (1) year from date of delivery transportation charges prepaid for
the account of the Purchaser. The cost of demonstrating the need to diagnose such defects at the job site, if
required, shall be for the account of the Purchaser. Any product or component, or part thereof, so replaced or
repaired shall be warranted by Invensys for the remainder of the original warranty period or three (3) months,
whichever is longer. Any and all such replacements or repairs necessitated by inadequate preventative
maintenance, or by normal wear and usage, or by the fault of the Purchaser or power sources supplied by
others or by attack and deterioration under unsuitable environmental conditions shall be for the account of the
Purchaser. Invensys shall not be obligated to pay any costs or charges including “back charges” incurred by
the Purchaser or any other party except as may be agreed upon in writing in advance by Invensys.
89
MI 611-168 – January 2021
ISSUE DATES
MAR 1992
JUL 1995
JAN 1996
APR 1997
JUL 2001
JUN 2004
OCT 2005
SEP 2015
JAN 2021
Vertical lines to the right of text or illustrations indicate areas changed at last issue date.
Schneider Electric Systems USA, Inc.
70 Mechanic Street
Foxboro, MA 02035
United States of America
http://www.se.com
Copyright 1992-2021 Schneider Electric Systems
Global Customer Support
USA, Inc. All rights reserved.
Inside U.S.: 1-866-746-6477
Outside U.S.: 1-508-549-2424
https://pasupport.schneider-electric.com The Schneider Electric brand and any trademarks of
Schneider Electric SE or its subsidiaries are the
property of Schneider Electric SE or its subsidiaries.
All other trademarks are the property of their
respective owners.
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