Teledyne 354 Oxygen analyzer Instruction manual

INSTRUCTION AND SERVICE MANUAL
TBE/A! OXYGEN ANALYZERS
A
MODELS 350, 351, 352, 353, 354 & 355
CUSTOMER ORDER NOG 0 ~~
SALES ORDER No. Lo —[
reledyne Analytical Instruments
16830 Chestnut Street
City of Industry, CA 91749 — 1580
Phone: (626) 934— 1500, Fax: (626) 961 — 2538
TWX (910)584 — 1887 TDYANLY COID
Web: www.teledyne —ai.com 5
TABLE OF CONTENTS
INTRODUCTION. . .ecocccnorocrocerecoreoce acen. rs a 0000020000
DESCRIPTIONS
2.1 Models and Sensors.....eíereeoorcscsrreorecacreseroaaoroo
2.1.1 Model 350 * # Y & + XA AAA + + 0 + 4 # *
2.1.2 Model 351......e.recroo. ese esse e encroocrerreoo
2.1.3 Model 352... . г... ... y oscororesorovaroerosec e
2.1.4 Model 353......e...eo. e orceocrocsrerovrooreraeco
2.1.5 Model 354.......... + rscorcovorecanranaerercerco
2.1.6 DENSOFS....cocomoarascaracorcreoaracacooorado
2.2 Controls and Display. ........ 0 060400.000000080 08080008 .
2.2.1 Calibrate......we.esoocsoosrererccero eve us 2000
2.2.2 Off/On a « # 4 + + 5 + + + + ¥ 8% WF BREF EREDAR PED FEEDS EES
2.2.3 Alarm Setpoints (Models 352 and 354)........
2.2.4 Alarm Indication...evveveevrencnneeenns ....
2.2.5 Meter Display....... 0050000800020 008 ceva ..
2.3 Sensor Attributes and Circuit Requirements.......... ..
2.3.1 Sensor AttributeS...0..0.000000600000400000000080
« 2.3.2 Circuit Requirements... cvveerecevrnevsoonses
2.4 Individual Circuits and Components....._.ec-o.roesecocooo
2.4.1 Sensor Amplification Circuit.......eomceccooo
2.4.2 Reference Voltage Circuit. ...o..ecoe.ecocvcaso
2.4.3 Alarm Circuit - Standard Configurations.....
2.4.4 Alarm Logic Circuit. ...ce.ec.eocorcoresoaraceneo
2.4.5 The Meter, ......ooce.cocenocooenoccearo escoreco
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2.4.5.1 Analog Meter.......eooesocrcoroeo. .
2.4.5.2 Digital Meter......e.eoe.e. cose cans
2.4.6 Power Supply. ...o.ocorcasoocarerarermarcarmarao
INSTALLATION — BATTERY AND SENSOR. ...eocresoro. ere 500000
3.1 Battery Requirements. ....eoomeoscosonococsoocoacoaooacono
3.2 Battery Installation (Models 351, 352, 353, 354)..
3.3 Sensor Installation for B-6 Cell........ es see one 00000
3.4 Sensor Installation for B-5 Cell. .....r.eerecsooreocaooo
4 OPERATING INSTRUCTIONS. ......uueurssnnnennnsnnnsssnnenn,, 10
Model 350s se tte cre ana 10
Model ID 10
Model Usa TS 10
Model 353. e eerencaroosacan cena oarerenreCeaanone o 11
4.5 Model BHO ecco 12
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5 SERV ТСК INSTRUC TIONS т тов нет теле * + + # # + + + 5 5 5 6 à + + + EEE. 13
5 * 1 Troubleshoot ing. =" EEES A Eo. "70. 0409 4 04 4 0 9 48 чево тени 13
5. 1 * 1 Preliminary Checks > E 0 4 4 dada 0 04 0 4 4 4 4 X 4 8 4 13
5.1.2 Measurement Circuit Checks......e..e.eeec0... 13
5.1.3 Alarm Circuit Checks (Models 351, 352, 352
and 334). ......cccrorccoooococorarecocacove, 13 -
5.1.4 Meter Circuit Checks..........ee.o.conancoo. 14
5.2 Repair/Replacement...................e..0ecccom ree, 14
5.2.1 - Battery Replacement...........eeeeconcooce., 14
5.2.2 Sensor Replacement............eeoeococooooo. 15
5.2.3 Э1ваввешЬ1у. 55. ооооьовооьо оо очьовавово, 15
5.3 Manufacturing Test Procedures, ..........eooaccooocooa, 15
6 MODEL 355 INSTRUCTIONS. ............e.eecocneroconocenaoea 21
MATERIAL SAFETY DATA SHEET |
- SPARE PARTS LIST
REFERENCE DRAWINGS
INTRODUCTION
This manual provides operating instructions and service
for the 350 Series of oxygen analyzers.
information
Models 350, 351, 352, 353, 354, and 355 provide continuous and speci-
fic monitoring of oxygen. Each model is a fully independent unit
designed to monitor the oxygen content of an atmosphere to which its
sensor is exposed, Model 355 is quite different in physical арреаг-
ance from the other instruments in the series, For this reason,
separate coverage for Model 355 appears in Section 6. |
Models 350, 351, 352, 353, and 354 employ one of Teledyne Analytical
Instruments” patented electrochemical sensors (Cell Class B-6 or B-5),
which is acted upon by oxygen in the sample, to produce an electric
current, the strength of which is determined by the amount (concentra-
tion) of oxygen present.
Typical features of standard instruments are:
Model Number
350 351 352 353 354
Feature:
Power -—- None 4-0 4-0 29V 2-3
Batteries
Sensor MICRO—FUEL CELL
Alarms None Fixed LO, HI, Fixed LO, HI,
LO, Visual, Visual, LO, Visual, Visual,
Audio Audio, Audio, 30 Audio,
Sec, Audio 30 Sec.
Silence Audio
Silence
Display Analog Analog Analog Digital Digital
Meter Meter Meter LCD LCD
The sensors sample gaseous mixtures for oxygen by diffusion or, if
fitted with special adaptors, gases confined in closed systems or
containers.
Qualified personnel who service the TAI analyzers must be able to
read and follow schematics and know the basic functions and character-
istics of operational amplifiers. The only equipment required for
troubleshooting the analyzer is a Digital Volt Meter (DVM); however, a
way to simulate the sensors may be useful. Section 5.1 contains
suggestions for troubleshooting.
2
DESCRIPTIONS
2.1 Models and Sensors
2.1.1 Model 350
The Model 350 oxygen analyzer is a simple, lightweight unit
equipped with an easy-to-read analog meter with 1% oxygen gradua-
tions. Its rugged case will withstand industrial use. The
cable of the sensor holder plugs conveniently into a receptacle
in the case. The oxygen sensor directly drives the meter of the
Model 350 without batteries or electronic circuitry.
2.1.2 Model 351
Model 351 provides the features of the Model 350 with the addi-
tion of a fixed low-level alarm to indicate when the oxygen level
is below the setpoint. Model 351 provides both audible and
visual (indicator light) alarms. |
2.1.3 Model 352
Model 352 provides the features of the Model 351 with the addi-
tion of fully adjustable high- and low-level alarms to indicate
when the oxygen level is either above or below the selected
setpoints. The setpoints for the alarm circuits are adjusted by
digital pushbutton potentiometers that indicate the setpoint
directly in numerals. Model 352 provides both audible and visual
(indicator light) alarms.
2.1.4 Model 353
Model 353 contains a digital Liquid Crystal Display (LCD) instead
of the analog (pointer-type) meter. Because the digital display
is smaller, the Model 353 case is more compact. The digital
display produces alarm and battery level condition messages on
the display and provides a direct reading of the oxygen level in
numerals. Model 353 provides a fixed low-level alarm that is
both audible and visual (indicator light). Also, the Model 353
provides a pushbutton to silence the audible alarm for 30 sec-
onds, after which it reactivates automatically, unless the alarm
condition has been corrected.
2.1.5 Model 354
Model 354 provides the features of Model 353 with the addition
of fully adjustable high- and low-level alarms to indicate when
the oxygen level is either above or below the selected setpoints.
The setpoints for the alarm circuits are adjusted by digital
pushbutton potentiometers that indicate the setpoint directly in
numerals. |
2.2
2.1.6 Sensors
The standard sensor for these instruments is Teledyne’s patented
Micro-Fuel Cell, The B-6 cell, used in Model 350 only, resides
in a durable, corrosion-resistant holder. The holder connects to
the analyzer with a coiled cable plugged into a receptacle. The
cell connects to the analyzer electronics via spring-loaded con-
tacts on one end, pressed against mating contacts in the cell
holder. A screw-on cap holds the cell in its proper position
within the holder.
The B-5 electrochemical sensor assembly is used in all other
models of the 350 series (Models 351, 352, 353, and 354). The
cell and probe combine to form a single replaceable unit. A
coiled cord plugs into both the sensor assembly and the analyzer.
Replacement of the cell and probe is’ simple and requires no tools.
The Micro-Fuel Cell is a self-contained electrochemical trans—
ducer that requires no maintenance. It provides stable and
reliable readings throughout its useful life, after which it is
easily replaced.
Because the Micro-Fuel Cell generates no signal in the absence of
oxygen, no zero standardization is required. When practical, the
analyzer should be calibrated to the oxygen content of air; this
procedure is described in detail later.
Controls and Display
2.2.1 Calibration
The face of each instrument contains a control potentiometer to
adjust for variations in sensor output. When the sensor is
exposed to a known oxygen concentration, the "Calibrate!" knob is
turned to adjust the meter indication to the known concentration.
The known oxygen concentration of air (20.9%) is used as the
standard for this adjustment whenever it is practical.
2.2.2 OFf/On
Use the Off/On switch to turn Models 351, 352, 353, and 354 on
and off. Model 350 does not use batteries or powered electronic
circuits, so it does not require an Off/On switch. Models 351
and 352 incorporate a "Batt, Test" position into the Off/On
switch for checking the condition of their batteries against a
scale indication on their meters. Battery level condition for
Models 353 and 354 appears on the LCD display and will be des-
cribed later.
2.2.3 Alarm Setpoints (Models 352 and 354)
Models 352 and 354 are equipped with one HI and one LOW oxygen
level alarm. The alarms for Models 352 and 354 are fully
adjustable by means of digital pushbutton potentiometers. By
2.3
pressing the minus (~) pushbutton below one of the numerals on
the face of the control, that numeral is decreased by one count.
Conversely, pressing the plus (+) pushbutton above a numeral adds
one count to that numeral. The setpoint indicators represent
percent oxygen settings in increments of 1% (right-hand numeral)
and 10% (left-hand numeral).
2.2.4 Alarm Indication
Models 351 and 353 have only low-level alarms. Models 352 and
354 have fully adjustable high- and low-level alarms. Models
351, 352, 353, and 354 provide both audible and visual alarm
indication in the event that the measured oxygen level deviates
from the alarm setpoint. If desired, on Models 352 and 354 you
can silence the audible alarm for periods of 30 seconds each by
pressing the "Audio Silence" pushbutton on the front panel. The
audible alarm will sound again after the 30-second time period,
unless the alarm condition has been corrected. The visual alarm
indicator continues to warn of the alarm condition until it is
corrected, regardless of the state of the audible device.
2.2.5 Meter Display
Models 350, 351, and 352 come with a very accurate analog
(pointer-and-scale type) meter. Standard instruments contain a
mirrored scale on the face of the meter, so the operator can
align the pointer accurately with its reflection on the mirrored
scale and avoid reading errors due to parallax.
The meters on Models 351 and 352 include a Battery Check scale
that indicates the battery condition while the power switch is in
the "BAT TEST" position.
Models 353 and 354 provide oxygen level indication in numerals on
the digital LCD rather than the pointer-scale type analog meter.
Also, the digital readout provides alarm and low battery messages
in words when the indicated condition exists,
Sensor Attributes and Circuit Requirements
2.3.1 Sensor Attributes
Each of the instruments uses the Micro-Fuel (galvanic-type) cell.
A thermistor/resistor circuit compensates for temperature-related
effects of the sensor. The B-6 Micro-Fuel Cell uses a probe
assembly with built-in thermistor circuitry. The B-5 Micro-Fuel
Cell Assembly contains a sensor and the thermistor circuitry in a
single unit.
The Micro Fuel Cell does not require an external excitation
voltage source; it will independently produce a current propor-
tional to the amount of oxygen present in the gas mixture sur-
rounding it.
2.4
A typical Micro-Fuel Cell, the B-6, produces 300 microampere
(+20%) of current in 100% oxygen. The B-5 sensor assembly
produces 100 millivolts (+20%) in 100% oxygen.
2.3.2 Circuit Requirements
The current from the Micro-Fuel Cell passes through a network
consisting of a thermistor and two resistors within the probe
asgembly, and then through a span potentiometer (span pot) in the
analyzer unit. This converts the non-compensated cell current
into a temperature-compensated voltage. The span pot is used to
calibrate the sensor, and an amplifier is used to bring the
voltage up to a suitable level for driving the meter and alarm
circuitry. Because the B-5 sensor assembly is one unit including
the thermistor circuitry, the B-5 produces voltage rather than
current output.
As an example, refer to the Model 351 Schematic provided in the
drawings section. The Micro-Fuel Cell is shown with its compen-
sating circuitry connected to the span pot. The slider of the
span pot is connected to the non-inverting input of operational
amplifier Alc, which amplifies the signal. Offset adjustment for
the amplifier is provided by P-1.
Individual Circuits and Components
Each of the analyzers in this product series contains some of the
following features:
Sensor amplification circuit
Reference voltage circuit
Alarm circuit
Alarm bypass logic
Meter (analog or digital)
Power supply
Oa 69 ВО
This chart lists each feature and indicates the analyzers in
which that feature is found. Use the chart for reference when
you perform the troubleshooting tests outlined in section 5.
section: Used in:
350 351/352 353/354
Sensor amplification circuit NO YES YES
Reference voltage circuit NO YES YES
Alarm Circuit NO YES YES
Alarm Bypass Logic NO NO YES
Meter (analog) YES YES NO
Meter (digital) NO NO YES
Power Supply NO YES YES
2.4.1 Sensor Amplification Circuit
See Section II —- "DESCRIPTIONS ~ Sensor Attributes and
Circuit Requirements."
2.4.2 Reference Voltage Circuit
The circuits for the alarms require a reference voltage to work
properly. Reference voltage is provided by a band-gap reference,
IM385, which acts like a very precise and stable zener diode,
producing 1.25 volts (or 2.50 volts). Some circuits use an
amplifier to lower the impedance of the reference and produce a l
volt reference for other parts of the circuit. An incorrect
reference voltage can be caused by a bad reference IC, by too
high a resistance feeding it, or by too low a resistive load on
it. Problems with the alarm setpoints may indicate a faulty
reference voltage circuit or an improper reference voltage level.
2.4.3 Alarm Circuit - Standard Configurations
The available alarm configurations are:
Type of alarm Used in
350 351 352 353 354
High - adjustable NO NO YES NO YES
Low =~ adjustable NO NO YES NO YES
Low - fixed at 19,5% NO YES NO YES NO
30-Second Silence NO NO NO YES YES
Battery Condition NO YES YES YES YES
In each case an operational amplifier, used as a comparator,
determines whether the measured parameter (oxygen level or bat-
tery voltage) is greater or less than a preset voltage, The
outputs of the comparators are fed to a prescribed logic circuit,
then to the alarm output devices (L.E.D., beeper, or LCD) as
determined by the alarm configuration.
As an example, refer to the Model 351 Schematic in the drawings
section. R7 and ZD1 produce the 1.25 volt reference. A fixed
portion (0.78 volts) of the 1.25 volts is fed to Aid, which
compares that voltage with the oxygen level from Alc; if that
level drops below 0.78 volts, the output of Ald goes positive,
turns on transistor Ql via D3 and R17, and turns on the LED and
the beeper.
2.4.4 Alarm Logic Circuit
Models 353 and 354 have logic that allows the beeper to be silen-
ced for 30 seconds by pressing the switch on the front of the
unit,
Comparators A3a, A3b, and A3c can all generate alarms (see sche-
matics for Models 351 and 352). A3a is the high alarm, A3b is
the low alarm, and A3c is the fixed low alarm. Diodes D5; D6,
D7, D10, Dil, and D14 are used to "or" the outputs to the approp-
riate display points on the LCD and also into the circuitry that
uses Ul.
Integrated circuit Ul performs the following functions via the IC
pin connections by which they are accessed. Pins 9 and 8 form an
oscillator that is disabled by pins 1 and 2. When enabled, it
causes the LED to blink via pins 3 and 4. Also, it fires the
beeper via D13, but only upon a low output at Ul pins 11 and 10,
The low condition at pins 11 and 10 exists under alarm conditions
except when the pushbutton is pressed (Models 353 and 354 only),
at which time C8 is discharged (and the alarm silenced) for 30
seconds, until CB has charged up again.
2.4.5 The Meter
2.4.5.1 Analog Meter. The analog (pointer-and-
scale-type) meters are simply driven via a trimpot from the 0-1
volt output of an operational amplifier. The meter is calibrated
by first mechanically zeroing it, next causing the voltage on it
to be 1 volt, and finally adjusting the series trimpot to achieve
a fullscale reading.
2.4.5.2 Digital Meter. Digital instruments use an
integrated analog-to-digital converter that needs no adjustment.
The auxiliary messages (Hi Alarm, Lo Alarm, Wait, and Lo Bat) on
the ICD are driven by "exclusive or" gates in a separate IC and
are enabled by a "high" to the appropriate line,
2.4.6 Power Supply
Power is supplied by batteries (Model 350 does not have a power
supply). Models 351 and 352 use 4 "C" cells and provide a balan-
ced plus and minus 3 volts (nominally) with the center connec-
tion of the batteries being the circuit reference (common or
ground). Models 353 and 354 use two 9-volt transistor batteries
and provide the common, or ground, connection by the use of an
amplifier.
М
Common (ground)
connection
The output voltage of the amplifier is the same as the voltage at
the junction of Ri and RZ. The amplifier can supply as much
current as needed for the rest of the circuitry.
3 INSTALLATION - BATTERY AND SENSOR
3.1
3.2
3.3
CAUTION:
3.4
Battery Requirements
Model 350: None
Models 351 and 352: Four size "C" batteries
Models 353 and 354: Two standard 9-volt batteries
Battery Installation (Models 351, 352, 353, 354)
i.
2.
3.
4.
Turn the power switch to the OFF position.
Move the sliding back panel to the right to expose the
battery compartment.
Install the correct batteries, observing proper polarity.
Close the sliding back panel.
sensor Installation for B-6 Cell
Do not scratch, puncture, or otherwise damage the Micro-Fuel Cell
membrane. Damage to the membrane will require sensor replacement.
NEVER PRESS ON THE SENSING SURFACE; you might damage the sensor.
1.
Hemove the new B-6 Micro-Fuel Cell from its protective bag.
Remove the shorting clip and tape from the contact plate.
Unscrew the holder cap from the sensor holder.
Place the Micro-Fuel Cell inside the sensor holder with the
cell’s membrane surface facing outward and the contact
plate facing inward.
Screw the cap back onto the sensor holder.
Check to see that the sensor cable is plugged into the
receptacle on the front of the analyzer.
Sensor Installation for B-5 Cell
1.
Remove the new B-5 sensor assembly from its protective
bag.
Remove the coiled cord from its protective bag.
Plug the cord into the sensor assembly. Then, plug the
other end of the cord into the analyzer.
4
OPERATING INSTRUCTIONS
4.1 Model 350
4.2
4.3
1. Be sure that the Micro-Fuel Cell sensor is installed
properly in the sensor holder.
Zu Connect the plug from the sensor holder cable into its
receptacle on the front panel of the analzyer.
3, Expose the sensor holder to air (20.9% oxygen) and adjust
the "Calibrate" control until the meter needle points
exactly to the calibration mark on the meter scale.
4, Model 350 is ready for use.
Model 351
1. © Hold the ON/OFF switch down in the BAT TEST position.
д, Check the meter for battery condition; replace batteries if
necessary.
de Be sure that the B-§ electrochemical oxygen sensor assembly
has the sensor cable plugged into it.
4, Connect the other end of the plug from the sensor cable
into 1ts receptacle on the front of the analyzer and turn
the instrument on.
6. Expose the sensor to air (20.9% oxygen) and adjust the
"Calibrate" control until the meter needle points exact-
ly to the calibration mark on the meter scale.
5, Check the fixed low alarm by adjusting the "calibrate"
control until the meter reads below 19.5%. The audible and
visual alarms should both activate,
7. Model 351 is ready for use.
Model 352
1. Hold the ON/OFF switch down in the BAT TEST position,
2. Check the meter for battery condition; replace batteries,
if necessary, |
de Be sure that the B-D electrochemical oxygen sensor has the
sensor cable plugged into it.
4. Connect the other end of the plug from the sensor cable
into its receptacie on the front of the analyzer and turn
the instrument on.
10
4.4
LA
8.
Calibrate the instrument to a known oxygen concentration:
As For sample concentrations at or below ambient oxygen
level (20.9%), expose the sensor to air. Adjust the
"Calibrate" control until the meter reads 21.
b. For sample concentrations above 20,9% and for best
accuracy, expose the sensor to calibration gas with
oxygen in a concentration higher than the sample (100%
oxygen calibration gas is preferred). Use an adaptor
to seal the sensor against outside air while exposing
it to the sample or calibration gas and introduce a
calibration gas. Adjust the "Calibrate" control to
the actual content of the standard, whether you are
using 100% oxygen or another certified calibration gas
mixture.
With the sensor in air, check the HI ALARM by setting the
HI ALARM setpoint potentiometer below 21% oxygen, The
audible and visual alarms should both activate. Readjust
the HI ALARM setpoint to the desired level.
Check the LO ALARM by setting its setpoint potentiometer
above 21% oxygen. The audible and visual alarms should
both activate. Readjust the LO ALARM setpoint to the
desired level.
Model 352 is ready for use,
Model 353
1.
2.
ds
4,
Place the power switch in the ON position. If LO BAT
appears on the display, then replace the batteries.
Be sure that the B-5 electrochemical oxygen sensor has the
sensor cable plugged into it.
Connect the other end of the sensor cable into its receb-
tacle on the front panel of the analyzer,
Check the fixed low alarm by adjusting the "calibrate"
control until the meter reads below 19.5%. The audible and
visual alarms should both activate. Press the AUDIO
SILENCE button and verify that the audible alarm silences
for about 30 seconds.
Calibrate the instrument to a known oxygen concentration:
a. For sample concentrations at or below ambient oxygen
level (20.9%), expose the sensor to air. Adjust the
"Calibrate" control until the LCD reads 21.
b. For sample concentrations above 20.9% and for best
accuracy, expose the sensor to a calibration gas
with oxygen in a concentration higher than the sample
11
6.
(100% oxygen calibration gas is preferred). Use an
adapter to seal the sensor against outside air while
exposing it to the sample or calibration gas and
introduce a calibration gas. Adjust the "Calibrate"
control to the actual content of the standard, whether
you are using 100% oxygen or another certified
calibration gas mixture. |
Model 353 is ready for use.
4.5 Model 354
1.
Place the power switch in the ON position. If LO BAT
appears on the display, then replace the batteries.
Be sure that the B—5 electrochemical oxygen sensor has
the sensor cable plugged into it.
Connect the other end of the sensor cable into its гесер-
tacle on the front panel of the analyzer.
Calibrate the instrument to a known oxygen concentration:
a. For sample concentrations at or below ambient oxygen
level (20.9%), expose the sensor to air. Adjust the
"Calibrate" control until the LCD reads 21.
b. For sample concentrations above 20.9% and for best
accuracy, expose the sensor to a calibration gas
with oxygen ina concentration higher than the
sample (100% oxygen calibration gas is preferred).
Use an adapter to seal the sensor against outside
air while exposing it to the sample or calibration
gas and introduce a calibration gas. Adjust the
"Calibrate" control to the actual content of the
standard, whether you are using 100% oxygen or
another certified level.
With the sensor in air, check the HI ALARM by setting
the digital HI ALARM setpoint potentiometer below 21%
oxygen. The audible and visual alarms should both
activate. Press the AUDIO SILENCE button and verify that
the audible alarm silences for about 30 seconds. Readjust
the HI ALARM setpoint to the desired level.
Check the LO ALARM by setting the digital LO ALARM set-
point potentiometer above 21% oxygen. The audible and
visual alarms should both activate, Press the AUDIO
SILENCE button and verify that the audible alarm si-
lences for about 30 seconds. HReadjust the LO ALARM
setpoint to the desired level.
Model 354 is ready for use.
12
5 SERVICE INSTRUCTIONS
5.1 Troubleshooting
The following is a general outline of the troubleshooting proce—
dure,
logic of the situation, and particular faults may require steps
not mentioned. |
5.
а.
1.1
.1.2
1.3
in practice, many steps could be skipped, according to the
Preliminary Checks
Check for physical damage. Be especially aware that damage
due to abuse or misuse may void the warranty for the
instrument or the Micro-Fuel Cell.
Check the sensor: calibrate at 100% oxygen, then recheck in
air; should read 21 +1% (Models 352, 353, and 354).
Check the instrument with a good sensor.
Check the sensor connections.
Check the batteries, connections, and voltages.
Measurement Circuit Checks
Check reference voltages (if alarms are used).
Check the sensor amplifier.
Check the span pot continuity and operation.
Alarm Circuit Checks (Models 351, 352, 353, and 354)
Check the alarm pots for continuity and operation.
Check the voltages at the inputs of the comparators.
Check the comparator input/output match. If the positive
input is of greater magnitude than the negative input, the
output voltage should be positive; if the positive input
is smaller than the negative input, then the output voltage
should be negative.
Check the voltage at each end of the setpoint potentiometer.
Check the voltage at the slider to be sure that it
corresponds with the physical setting.
If all else checks okay, test the logic circuit (refer to
Section 2.4.4 for more information).
If you find no problems with the alarm circuit, and yet the
LED does not light or the beeper does not beep, then test or
replace the LED or beeper, as necessary.
13
5.2
5.1.4 Meter Circuit Checks
a. Check the meter connections.
b. Check the continuity between the main circuit and the meter.
с. Check the meter response to changes in input signal.
d. Check the word messages of digital meters by simulating the
conditions that would activate them. For example, check the
alarm messages by adjusting the setpoints until the instru-
ment is in an alarm condition; check the "LO BAT" message by
deliberately providing the instrument with insufficient
battery voltage.
Repair/Replacement
CAUTION:
ICs are susceptible to damage from static electricity. Ground
yourself and your scldering iron before working on the unit.
Wear natural fibers — no nylon or polyester!
Do not touch the circuit boards with your fingers. Contamination
from body salts or oils may affect the accuracy of the unit.
Battery Requirements
Model 350: None
Models 351 and 352: Four Size "C" batteries
Models 353 and 354: Two standard 9-volt batteries
5.2.1 Battery Replacement
Models 351, 352, 353, and 354
1. Place the power switch in the OFF position.
2. Move the sliding back panel to the right to expose the
battery compartment.
3. Remove old batteries.
4. Install the correct batteries, observing proper polarity.
5, Close the sliding back panel.
14
5.3
5.2.2 Sensor Replacement
CAUTION:
Do not scratch, puncture, or otherwise damage the sensor's mem-
brane. Damage to the membrane will require sensor replacement.
NEVER PRESS ON THE SENSING SURFACE: you might damage the sensor.
Micro-Fuel Cell - B-6
1. Remove the new B-6 Micro-Fuel Cell from its protective
bag. Carefully remove the shorting clip.
2.. Unscrew the holder cap from the sensor holder and remove
the existing Micro-Fuel Cell,
3. Place the new Micro-Fuel Cell inside the sensor holder with
the cell's membrane surface facing outward, and the electri-
cal contacts facing inward.
4. Screw the cap back onto the sensor holder.
5. Check to see that the sensor cable is plugged into the
receptacle on the front of the analyzer.
Micro-Fuel Cell — B-5
i. Remove the new B-5 Micro-Fuel cell assembly from its
protective bag.
2. Unplug the coiled cord from the old B-5 cell assembly.
3. Plug the coiled cord into the new B—5 cell assembly.
a, Discard the old B-5 cell assembly.
5.2.3 Disassembly ~ All Models
Hemove the four screws at the corners of the underside of the
instrument, then pull the top cover up and away from the
electronics front panel and PC board.
Manufacturing Test Procedures
The following test procedures are those actually used in Tele-
dyne’s testing department. They may provide information or sug-
gestions on how to perform troubleshooting tests, as well, so we
are including them with your service manual.
Please note that the test procedures depend upon the use of a
"simulator" to take the place of the measuring cell during test-
ing of the instrument. The cell simulator can be purchased from
Teledyne Electronic Devices.
15
1.5 Y
Battery:
Or, a simple circuit such as the one illustrated in the sketch
can be constructed to substitute for the simulator.
Micro-Fuel Cell Simulator
5 K
AAA)
1.5 volt battery
Current Source
150 K
10 K
+ 0
T Adjust for 21 mv
O
Voltage Source
16
TEST PROCEDURE
MODEL 350
Be sure that the meter reads zero: adjust the mechanical meter
zero, if necessary.
Connect the probe assembly. Set the Micro-Fuel Cell simulator
selector switch to the C-1 position: connect the simulator to
the probe assembly (positive lead to the outer spring contact,
negative lead to the center spring contact),
Simulate 100% oxygen and adjust the CALIBRATE control until the
meter reads 100.
Similate 20.9% oxygen. The meter needle should coincide with the
red CAL mark on the meter scale. Read just the mechanical meter
zero until the needle points exactly to the CAL mark.
17
10.
il.
TEST PROCEDURE
MODELS 351 and 352
Before supplying power to the unit, be certain that the pointer
of the readout meter points exactly to zero. Adjust the mechan-
ical zero of the meter, if necessary,
Slide open the battery panel at the rear of the instrument, and
install four size "C" alkaline batteries, observing proper polar-
ity as shown. Place the power switch in the ON position.
Adjust trimmer P-1 on the PC Board until the meter reads exactly
zero.
Connect the probe assembly. Set the Micro-Fuel Cell simulator to
a 70 microampere output with the selector switch in the A-3 pos-
ition and the attenuator in the CAL position. Connect the simul-
ator to the probe assembly (positive lead to the outer spring
contact and the negative lead to the center spring contact).
Set the attenuator of the simulator to 100 %. Adjust the CALI-
BRATE control of the test unit until the meter reads 100.
Set the attenuator of the simulator to CAL (21%). The meter
needle should coincide with the red CAL mark on the meter scale,
Readjust the mechanical meter zero until the needle points exact-
ly to the CAL mark,
Set the HIGH limit to read 30% and the LOW limit to read 25%.
Offset the CALIBRATE control so that the display reads above 30%.
The HIGH warning (HI ALARM) (Model 352 only) should be shown on
the display and the light should flash. The audible alarm should
sound, as well. Alarming should occur within + digit of the HI
ALARM setpoint.
Turn the CALIBRATE control until the meter reads below 25%; LOW
warning should appear on the meter within +1 digit of the set-
point, and the audible and visual alarms should energize.
Set the LOW limit to 10%. Slowly adjust the CALIBRATE control to
lower the meter reading; the LOW warning should appear at 19.5%
+2%. The audible and visual alarms should energize.
Turn the unit off and replace the two batteries in the positive
half of the power supply with a variable DC power supply. Place
a capacitor (300 to 600 mfd.) across the power supply to lower
the source impedance.
Turn the unit on and vary the supply voltage from 3 volts to 1.8
volts while holding the power switch in the BAT TEST position.
The pointer of the meter should cross the BATTERY REPLACE mark
when the supply voltage is 2.0 +0.1 volts.
18
10.
il.
TEST PHOCEDURE
MODELS 353 and 354
Connect a 9V battery to the battery terminals, and switch on the
instrument. Connect a current meter across the power switch
terminals. Switch off the instrument. The current reading
should be below 1 má. Switch the instrument on again and remove
the current meter.
Connect the DVM negative lead to pt. #5 (ground) on the main PC
Board and the positive lead to pt. #7. The DVM should indicate
+4.5 V, or half the battery voltage.
Connect DVM positive to pt. #9. DVM should read -4.5 V, or half
the battery voltage.
“Connect DVM positive lead to pt. #2; DVM should read 2.00
+.02 V.
Adjust trimmer P-1 on the PC Board until the meter reads exactly
Zero.
Connect the probe assembly. Set the Micro-Fuel Cell simulator to
a 70 microampere output with the selector switch in the 4-3
position and the attenuator in the CAL position. Connect the
simulator to the probe assembly (positive lead to the outer
spring contact and the negative lead to the center spring contact}.
Set the attenuator of the simulator to 100 %. Adjust the CALI-
BRATE control of the test unit so that the voltage out of A3a at
pin 16 is 2.000 volts. The display should read 100 +1.
Check the "SIG OUT" voltage; it should be 100 +2 millivolts.
Set the attenuator of the simulator to CAL (21%). The display
should read 21 +1.
Set the HIGH limit to read 30% and the LOW limit to read 25%.
Offset the CALIBRATE control so that the display reads above 30%.
The HIGH warning (HI ALARM) (Model 354 only) should be shown on
the display and the light should flash. The audible alarm should
sound also. Press the silence pushbutton; the audible alarm
should silence for 30 +10 seconds. Alarming should occur within
+ digit of the HI ALARM setpoint.
Turn the CALIBRATE control until the meter reads below 25%; LOW
warning should appear on the meter within +1 digit of the set-
point, and the audible and visual alarms should energize.
19
12.
13.
Set the LOW limit to 10%. Slowly adjust the CALIBRATE control to
lower the meter reading; the LOW warning should appear at 19.5%
+1%. The audible and visual alarms should energize.
Disconnect the battery and connect a variable power supply bet-
ween the battery leads. Vary the supply voltage from Y volts to
6.5 volts. At 6.5 +.2 volts, the LO BAT indicator should appear.
20
SPECIFICATIONS
Model Number
350 351 352 353 354
0-25% Range YES YES NO NO NO
0-100% Range NO NO YES YES YES
Analos Meter YES YES YES NO NO
Digital Meter (2 1/2 digit LCD) NO NO NO YES YES
Accuracy at Constant Temperature +2% +2% +2% +1% +1%
(% of Fuliscale)
Accuracy over Temperature Range +5% +5% +5% +5% +5%
(% of reading)
90% Response Time (Seconds) 13 13 13 13 13
0-100mV Voltage Output NO NO NO YES YES
Fixed Low Alarm at 19.5% 02 NO YES NO YES NO
2 Adjustable Alarms, (HI, LOW) NO NO YES NO YES
Audible and visual alarms NO YES YES YES YES
Temporary Audible Alarm Silence NO NO NO YES YES
MicroFuel Cell Type B~6 B-5 B-5 B-5 B-5
Warrantv/Expected |
Life (Months in Air) 18/36 18/36 18/36 18/36 18/36
Battery Type None 4-0 4-C 2-9v 2-9v
Battery Expected Life
In Months for Alkaline Cell - 8 8 8 8
Height, inches (mm) = ARA 5.8(147)H--—————————————
Width, inches (mm) .6(218) 5(267) 10.5(267) 8.6(218) 6(218)
Depth, inches (mm) .0(76) 5(114) 4,5(114) 4.5(114) 5(114)
Weight, in pounds 1.9 3.2 3.3 2.5 2.6
Weight, in grams (860) (1400) (1500) (1100) 1200)
Probe Length (feet) 8 8 8 8 8
Operating Temperature Range
a 0-500C/32~122°F
LJ EE eo er A Pr a
CELL
MICRO-FUEL CELLS
FOR MODELS 350, 551, 352, 353, AND 354
WARRANTED
PEHCENT OXYGEN ANALYZERS
EXPECTED 90% QUTPUT
CLASS LIFE LIFE HESPONSE IN AIR
B—5 18 MOS. 36 MOS. 13 SEC. 21mVY +20%
IN AIR
B-6 18 MOS. 36 MOS. 13 SEC. .30mA +20%
IN AIR
NOTE: Specifications are at 25°C (77°F),
a
MATERIAL SAFETY DATA SHEET
Section I ~ Product Identification
Product Name: Micro Fuel Cells r all classes execpt A~2, A-3,
| А-5, B-2F and B-2CF.
Electrochemical Oxygen Sensors, all classes
execpt R-19,
Mini micro-fuel cells, all classes,
Manufacturer: Teledyne Analytical Instruments
Address: 16839 Chestnut Street, City of Industry, CA 91749
Phone Number: (818) 961-9221
MSDS Prepared By: Chuck Molloy
Date Prepared or Last Revised: 3-31-88
Emergency Phone No.: (818) 961-9221
section IT ~ Physical and Chemical Data
— Chemical and Common Names: Potassium Hydroxide (KOH) 15%
Granular Lead (PP) pure
CAS Number: KOH 1319-58-32
Pb 7439-921
Melting Point/Range: -10 to 0 Deg. C
Boiling Point/Range: 108 to 115 Ред. С
Specific Gravity: 1.09 @ 20 Ред. С
pH: >14
Solubility in Waters: Completely soluble
Percent Volatiles by Volume: None
Appearance and Odor: Colorless, odorless solution
li
Section III - Physical Hazards
Potential for Fire and Explosion: The electrolyte in micro-fuel
Cells is not flammable. There are no fire or explosion hazards
associated with micro-fuel cells.
Potential for Reactivity: The sensors are stable under normal
conditions of use. Avoid contact between the sensor electrolyte
and strong acids.
ei ii Tr rushers mala
Primary Route(s) of Entry: Ingestion, Eye/Skin Contact
Exposure Limits: OSHA PEL .05 mg/cu.m. (Pb)
ACGIH TLV 2 mg/cu.m. (KOH)
Effects of Overexposure:
Ingestion: The electrolyte could be harmful or fatal if
swallowed. Oral 1050 (ВАТ) = 2433 mg/kg
Eye: The electrolyte is corrosive and eye contact could
result in permanent loss of vision.
Dermal: The electrolyte is corrosive and skin contact could
result in a chemical burn. |
Inhalation: Liquid inhalation is unlikely.
Signs/Symptoms of Exposure: Contact with skin or eyes will cause
a burning sensation and/or a soapy
feeling for skin contact.
Medical Conditions Aggravated by Exposure: None
Carcinogenicity:
NIP Annual Report on Carcinogens: Not listed.
LARC Monographs: Not listed.
OSHA: Not listed.
Other Health Hazards: Lead is listed as a chemical known to the
State of California to cause birth defects
or other reproductive harm.
Section Y - Emergency and First Aid Procedures
Eye Contact: Flush eyes with water for at least 15 minutes and
get immediate medical attention. | `
Tr aT REL
CELLS, MSD
Skin Contact: Wash affected area with plenty of water and remove
contaminated clothing, If burning persists, seek .
medical attention. RE
Ingestion: Give plenty of cold water. Do not induce vomiting, Co
Get medical attention. Lo e
Inhalation: Liquid inhalation is unlikely,
Section VI - andling Information
Handling Precautions: Note: The Oxygen sensors are sealed and
under normal Circumstances, the contents of the sensors do not
present a health hazard. The following information is given as
a guide in the event that a cell leaks.
Protective Clothing: Rubber gloves, chemical splash goggles.
Clean-up Procedures: Wipe down the area several times with a wet
paper towel. Use a fresh towel each time.
Protective Measures during Cell Replacement: Before opening the
bag containing the cell, check the cell for leakage. If the
cell leaks, do not open the bag. If there is liquid around the
cell while in the instrument, put on gloves and eye protection
before removing the cell.
Disposal: Should be in accordance with all applicable state,
local and federal regulations.
ea CF
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SE
SPARE PARTS LIST FOR MODEL 354
QIY. PART NUMBER DESCRIPTION
Al76 ALARM
Ese | CLIP AND WIRE, BATTERY
B30171 ASSEMBLY, PC BOARD (ICD)
B40304 ASSEMBLY, PC BOARD
B39955 — SENSOR, CLASS B-5
1 K35 KNOB
1 Jl JACK
1 L154 LED
1 L156 LENS, RED
1 P322 POT, 5 K (Bourns #3852-282-502A) |" *
2 P443 POT, 100 K (DIGITAL)
A MINIMUM CHARGE OF $20.00 I5 APPLICABLE TO SPARE PARTS ORDERS.
IMPORTANT: Orders for replacement parts must include the model and serial
number of the equipment for which the parts are intended. This information
is available on the Specific Application page in the front of this manual.
Send orders to: TELEDYNE ANALYTICAL INSTRUMENTS
16830 CHESTNUT STREET
CITY OF INDUSTRY, CA 91740-1580
TELEPHONE: (818) 961-9221
TWX: 910-584-1887 TDYANYL COID
REFERENCE DRAWINGS
MODEL 354
C~40303 OUTLINE DIAGRAM
C-40306 SCHEMATIC
C-40308 WIRING DIAGRAM
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