CS420-L and CS425-L Druck’s

Models PDCR 1830 and 1230

Pressure Transducers

Revision: 12/07

C o p y r i g h t © 2 0 0 0 - 2 0 0 7

C a m p b e l l S c i e n t i f i c , I n c .

The CS420-L and CS425-L Pressure Transducers are manufactured by Druck

Incorporated. Druck’s conditions of sale and return policy apply to these items.

Products may not be returned without prior authorization. To obtain an RMA number contact Druck, Inc., phone (203) 746-0400. NOTE: if the product has been exposed to hazardous media, it must be fully decontaminated and neutralized prior to return to

Druck.

CS420-L/CS425-L (Druck PDCR Series)

Table of Contents

PDF viewers note: These page numbers refer to the printed version of this document. Use the Adobe Acrobat® bookmarks tab for links to specific sections.

1. General Information

.....................................................1

2. Specifications

..............................................................1

3. Installation

....................................................................2

3.1 Vent Tubes................................................................................................2

3.2 Dislodging Bubbles ..................................................................................2

3.3 Transient Protection..................................................................................2

3.4 Temperature Fluctuations .........................................................................2

4. Datalogger - Sensor Connections

..............................2

4.1 Six-Wire Configuration ............................................................................3

4.2 Four-Wire Configuration..........................................................................3

5. Programming

...............................................................3

5.1 Using Short Cut ........................................................................................3

5.2 Using CRBasic, Edlog, or the Keyboard/Display.....................................4

5.2.1 Calculating the Multiplier ...............................................................4

5.2.2 Calculating the Offset .....................................................................5

5.3 Fine Tuning the Excitation and Input Range ............................................5

5.4 Increasing the Resolution .........................................................................6

6. CRBasic Program Examples

......................................7

6.1 Wiring for the Program Examples............................................................7

6.1.1 BrFull Instruction (4-Wire Full Bridge Measurement)...................7

6.1.2 BrFull6W Instruction (6-Wire Full Bridge Measurement) .............7

6.2 CR800, CR850, and CR1000 Programs ...................................................8

6.2.1 BrFull Instruction (4-Wire Full Bridge Measurement)...................8

6.2.2 BrFull6W Instruction (6-Wire Full Bridge Measurement) .............8

6.3 CR3000 Programs.....................................................................................9

6.3.1 BrFull Instruction (4-Wire Full Bridge Measurement)...................9

6.3.2 BrFull6W Instruction (6-Wire Full Bridge Measurement) .............9

6.4 CR5000 Programs...................................................................................10

6.4.1 BrFull Instruction (4-Wire Full Bridge Measurement).................10

6.4.2 BrFull6W Instruction (6-Wire Full Bridge Measurement) ...........10 i

CS420-L/CS425-L Table of Contents

7. Edlog Program Examples

.........................................11

7.1 CR10(X), CR510, and CR500 Examples............................................... 11

7.1.1 Instruction 6 (4-Wire Full Bridge Measurement)......................... 11

7.1.2 Instruction 9 (6-Wire Full Bridge w/Excitation).......................... 12

7.2 CR23X and 21X Examples.................................................................... 13

7.2.1 Instruction 6 (4-Wire Full Bridge Measurement)......................... 13

7.2.2 Instruction 9 (6-Wire Full Bridge w/Excitation).......................... 14

8. Using Multiplexers

.....................................................15

8.1 Examples................................................................................................ 15

8.1.1 Wiring For One Druck Multiplexer/Datalogger........................... 15

8.1.2 Multiplexer Connection................................................................ 16

8.1.3 CRBasic Multiplexer Examples ................................................... 16

8.1.4 Edlog Example ............................................................................. 19

9. Maintenance

...............................................................20

9.1 Every Visit, At Least Monthly............................................................... 20

9.2 Every Three Months .............................................................................. 21

9.3 Every Two to Three Years or on a Rotating Schedule........................... 21

10. Troubleshooting

.......................................................21

Table

1. Conversion Factors .................................................................................... 4 ii

CS420-L and CS425-L Pressure

Transducers

This manual describes using the CS420-L and CS425-L pressure transducers with

Campbell Scientific’s CR800, CR850, CR1000, CR3000, CR5000, CR10(X), CR23X,

CR510, CR500, and 21X dataloggers. Information provided in the manual includes datalogger-to-sensor connection, datalogger programming, use of multiplexers in the system, and maintenance requirements.

1. General Information

The CS420-L is Druck’s model PDCR 1830-8388; the CS425-L is model

PDCR 1230-8388. Druck PDCR 1230 and 1830 pressure transducers are used for surface and ground water level measurement. The CS425-L sensor can be ordered in pressure ranges between 5 and 900 psi and has an accuracy of

±0.25% of the Full Scale Range (FSR); the CS420-L can be ordered in pressure ranges between 1 and 900 psi and has an accuracy of ±0.1% FSR.

Further information on sensor construction can be obtained from Druck’s 1230 or 1830 Pressure Transducer brochures.

2. Specifications

Overpressure

8x for 1 and 2.5 psig range

6x for 5 psig range

4x for 10 psig and above ranges

Excitation Voltage

10 Volts at 5 mA maximum

Output Voltage

25mV for 1 psig range

50mV for 2.5 and 5 psig ranges

100mV for ranges 10 psi and above

Output is ratiometric to supply

Combined non-linearity, hysteresis and repeatability

±0.1% of Full Scale, Best Fit Straight Line for CS420-L

±0.25% of Full Scale, Best Fit Straight Line for CS425-L

Operating Temperature Range

-20ºC to +60ºC

Compensated Temperature Range

-2ºC to +30ºC

Long Term Stability

Typically ±0.1 mV/annum

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CS420-L and CS425-L Pressure Transducers

3. Installation

3.1 Vent Tubes

A vent tube incorporated in the cable vents the sensor diaphragm to the atmosphere. This eliminates the need to compensate the water level measurement for changes in barometric pressure.

To prevent water vapor from entering the inner cavity of the sensor, the transducers are typically shipped with the vent tubes sealed. Before operation, visually confirm the vent tube is open. The vent tube opening must terminate inside a desiccated enclosure or a Campbell Scientific DES2 desiccant case.

NOTE The desiccant must be changed regularly.

3.2 Dislodging Bubbles

While submersing the sensor, air bubbles may become trapped between the pressure plate and the water surface, causing small offset errors until the bubbles dissolve. Dislodge these bubbles by gently shaking the pressure transducer while it is under water.

CAUTION Do not hit the sensor against the well casing or other solid surface while dislodging the bubbles, because the diaphragm could be damaged.

3.3 Transient Protection

Campbell Scientific recommends transient surge protection for sensors installed in lightning prone areas. No lightning protection is capable of withstanding a direct hit, but surge protectors afford a degree of protection for near misses. Surge protection can be provided by Campbell Scientific’s

SVP48 Surge Voltage Protector. When an electrical surge occurs, the surge protectors involved may need to be replaced.

3.4 Temperature Fluctuations

Temperature fluctuations can be minimized by using a minimum cable burial depth of six inches and a sensor submersion depth of one foot. Also, if your site may experience extreme temperature fluctuations, the transducer must be measured using the six-wire configuration.

4. Datalogger - Sensor Connections

The transducers are configured for a six-wire measurement. If using short cable lengths (< 100 feet) and extreme temperature fluctuations are not likely, a four-wire measurement can also be made reliably. The six-wire measurement is more accurate and the only advantage of the four-wire measurement is it requires fewer analog channels. The four-wire configuration

2

CS420-L and CS425-L Pressure Transducers does not use the orange and black wires and the ends of each of these wires should be taped to prevent shorting.

4.1 Six-Wire Configuration

Datalogger

Excitation

AG (Analog Ground)

HI (Analog)

LO (Analog)

HI (Analog)

LO (Analog)

G (Ground)

CS420-L/CS425-L

Red (Supply Positive)

White (Supply Negative)

Orange (Excitation Monitor +)

Black (Excitation Monitor -)

Yellow (Signal Output +)

Blue (Signal Output -)

Clear (Shield)

4.2 Four-Wire Configuration

NOTE

Datalogger

Excitation

AG (Analog Ground)

HI (Analog)

LO (Analog)

G (Ground)

CS420-L/CS425-L

Red (Supply Positive)

White (Supply Negative)

Yellow (Signal Output +)

Blue (Signal Output -)

Clear (Shield)

The datalogger must be properly grounded. This reduces electromagnetic noise and chances of damage from lightning.

5. Programming

Use Short Cut, CRBasic, Edlog, or the datalogger Keyboard/Display to program the datalogger to read these sensors. All programming methods require the sensitivity value which is listed in the calibration certificate. A calibration certificate should accompany every sensor received from Druck. It is specific to the individual sensor; verify that the certificate and the sensor have the same serial number, and retain the certificate for your records.

5.1 Using Short Cut

Short Cut is the easiest and typically the preferred method for programming the datalogger. Short Cut will ask for the sensitivity which is listed on the calibration certificate. From this value, Short Cut will calculate the multiplier.

Choose either the “Manual Offset” or “Automatic Offset” module to adjust the transducer reading to the current water level reading.

Short Cut stores the Druck level data in the high resolution format. Short Cut also generates a wiring diagram that shows how to connect the Druck transducer to your datalogger.

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CS420-L and CS425-L Pressure Transducers

NOTE The sections that immediately follow are for CRBasic, Edlog, and Keyboard/Display users. Short Cut users can jump ahead to the Maintenance section (page 21).

5.2 Using CRBasic, Edlog, or the Keyboard/Display

For dataloggers programmed with CRBasic use the BrFull instruction to make a four-wire measurement and BrFull6W to make a six wired measurement.

For Edlog dataloggers use Instruction 6–Full Bridge Measurement to make a four-wire measurement or Instruction 9–Full Bridge with Measured Excitation to make a six-wire measurement. These instructions require a unique multiplier and offset to be calculated for each sensor. Your datalogger manual has a detailed explanation of these instructions and there is extensive help in the CRBasic editor. Also see the programming examples that start on page 7 of this document.

5.2.1 Calculating the Multiplier

The value for the sensitivity is listed on each transducer’s calibration certificate. It will be shown in units of either mV/V/psig or mV. Based on the units of sensitivity, choose one of the following equations to calculate the multiplier (M):

M =

1

Sensitivit y (mV/V/psig ) or M

Range (psig)

=

Sensitivit y (mV)/Suppl y Voltage (V)

After calculating M, use the conversion factor listed in Table 1 to convert the value to the desired engineering units.

TABLE 1. Conversion Factors

To change mb psig mb psig

To ft of water ft of water meters of water meters of water

Multiply by

0.0334883

2.306725

0.010207

0.70309

Example:

When Druck calibration certificate lists the following values for a sensor: sensitivity = 0.98 (mV/V)/psig

The multiplier is:

M = 1/(0.98 (mV/V)/psig)

= 1.02 psig/(mV/V)

If the desired engineering units are feet of water, the multiplier becomes:

(1.02 psig/(mV/V))*(2.306725 ft of water/psig)= 2.3529 ft of water/(mV/V)

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CS420-L and CS425-L Pressure Transducers

5.2.2 Calculating the Offset

The offset is calculated with the following procedure:

1. Program the datalogger using the calculated multiplier and an offset of 0 in either a 6-wire full bridge instruction (BrFull6W in CRBasic or

Instruction 9 in Edlog) or a 4-wire full bridge instruction (BrFull in

CRBasic or Instruction 6 in Edlog). Set the execution interval to one second.

2. Install the Druck transducer and a staff gauge at the same location or install the Druck transducer at a known depth.

3. If applicable, measure the depth using the staff gauge.

4. Use a keyboard display or PC to view the depth reading (refer to your datalogger manual for information about viewing real-time data).

5. Subtract the value displayed on the keyboard display or PC from the known depth or the staff gauge’s reading.

NOTE Always make sure your multiplier and offset are in the same units (e.g., feet, inches).

When using Edlog, large offsets may cause truncation of Final

Storage values resulting in fewer significant digits. If this is a problem, do the offset correction after the data is collected or use

Instruction 78 to store the data in the high resolution format.

Example:

A staff gauge and a Druck transducer are installed at the same location. If the staff gauge reads 10.07 feet and the value displayed on your keyboard display or PC is 10.56 feet, the offset for the Full Bridge Instruction is:

Offset = 10.07 ft - 10.56 ft

= -0.49 ft

Enter -0.49 for the offset parameter in the Full Bridge Instruction.

5.3 Fine Tuning the Excitation and Input Range

Choose a datalogger input range that is larger than the output from the sensor.

The voltage ranges and codes are listed in your datalogger manual, the

CRBasic help, or the Edlog help.

Typically 2500 mV excitation is used with CR800, CR850, CR1000, CR10(X),

CR510, or CR500 dataloggers; 5000 mV is used with CR3000, CR5000,

CR23X, and 21X dataloggers. To calculate the sensor output when a specific excitation is applied, use one of the following equations: output mV =

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CS420-L and CS425-L Pressure Transducers

NOTE or output mV =

( sup ply voltage V)

The value and units for the sensitivity are listed on Druck’s calibration certificate.

If the pressure range of the sensor is exceeded, the output voltage of the transducer could exceed the input range of the datalogger. For CRBasic dataloggers, NAN (not a number) indicates an overrange. For Edlog dataloggers, an overrange is represented by a -6999 in the data file or

-9999 in the monitor mode of the PC200W, PC400, LoggerNet, or PC208(W). If this occurs, decrease the recommended excitation voltage by ten percent. An open connection, such as a loose wire, can mimic an overrange condition.

5.4 Increasing the Resolution

NOTE The following instructions on increasing resolution are not necessary for most applications. We recommend jumping ahead to the program examples and getting your sensor up and running.

If you need a better measurement, refer back to this section.

To increase measurement resolution, adjust the excitation provided to the sensor so that the output is close to, but not exceeding the input range of the datalogger. An adjustment factor for the excitation can be calculated using the following equation: adjustment factor = input range mV output mV

Example:

A CR3000 datalogger is used to measure a Druck transducer. The Druck calibration certificate lists the following values: pressure range: 10 psig

(mV/V)/psig

If a 5000 mV (5 V) excitation is applied to the sensor, the output of the sensor will be: output mV = (10 psig)(1.1 (mV/V)/psig)(5 V)

= 55 mV

The input ranges for the CR3000 are: ±20, ±50, ±200, ±1000, and ±5000 mV.

The sensor output of 55 mV exceeds the ±50 mV range, but using the ±200 mV range decreases the resolution. By calculating and applying an adjustment factor, you obtain the best measurement for your sensor.

6

CS420-L and CS425-L Pressure Transducers adjustment factor = input range output

The excitation adjusted to output 50 mV is: adjusted excitation

= (original excitation)*(calculated adjustment factor)

= (5000 mV)*(.909)

= 4545 mV

Use 4545 mV to excite the sensor instead of 5000 mV within either the BrFull or BrFull6W instruction.

6. CRBasic Program Examples

6.1 Wiring for the Program Examples

6.1.1 BrFull Instruction (4-Wire Full Bridge Measurement)

Datalogger

Excitation

Input

Input

Analog Ground

E1

H1

L1

AG

CS420-L/CS425-L

Red (Supply +)

Yellow (Output +)

Blue (Output -)

White (Supply -)

The orange and black wires are not used and the ends of these wires should be taped to prevent shorting.

6.1.2 BrFull6W Instruction (6-Wire Full Bridge Measurement)

Datalogger CS420-L/CS425-L

Excitation

Input

Input

E1

H1

L1

Red (Supply +)

Orange (Monitor +)

Black (Monitor -)

Input

Input

H2

L2

Yellow (Output +)

Blue (Output -)

An. Ground AG White (Supply -)

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CS420-L and CS425-L Pressure Transducers

6.2 CR800, CR850, and CR1000 Programs

6.2.1 BrFull Instruction (4-Wire Full Bridge Measurement)

'CR1000, CR800, CR850

'4wire configuration

Public Depth_Ft

DataTable (WtrData,1,-1)

(0,15,Min,10)

Sample

EndTable

BeginProg

(15,Min,0,0)

BrFull (Depth_Ft,1,mV2500,1,Vx1,1,2500,True ,True ,0,250,2.3529,-0.49)

WtrData

NextScan

EndProg

6.2.2 BrFull6W Instruction (6-Wire Full Bridge Measurement)

'CR1000, CR800, CR850

'6wire configuration

Public Depth_Ft

DataTable (WtrData,1,-1)

DataInterval

(1,Depth_Ft,FP2)

EndTable

BeginProg

(15,Min,0,0)

BrFull6W (Depth_Ft,1,mV2500,mV25,1,Vx1,1,2500,True ,True ,0,250,2.3529,-0.49)

CallTable

NextScan

EndProg

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CS420-L and CS425-L Pressure Transducers

6.3 CR3000 Programs

6.3.1 BrFull Instruction (4-Wire Full Bridge Measurement)

'CR3000

'4 Wire configuration

Public Depth_Ft

DataTable (WtrData,1,-1)

(0,15,Min,10)

Sample

EndTable

BeginProg

(15,Min,0,0)

BrFull (Depth_Ft,1,mv5000,1,Vx1,1,5000,True ,True ,0,250,2.3529,-0.49)

WtrData

NextScan

EndProg

6.3.2 BrFull6W Instruction (6-Wire Full Bridge Measurement)

'CR3000

'6wire configuration

Public Depth_Ft

DataTable (WtrData,1,-1)

DataInterval

(1,Depth_Ft,FP2)

EndTable

BeginProg

(15,Min,0,0)

BrFull6W (Depth_Ft,1,mv5000,mV50,1,Vx1,1,5000,True ,True,0,250,2.3529,-0.49)

CallTable

NextScan

EndProg

9

CS420-L and CS425-L Pressure Transducers

6.4 CR5000 Programs

6.4.1 BrFull Instruction (4-Wire Full Bridge Measurement)

'CR5000

'4 Wire configuration

Public Depth_Ft

DataTable (WtrData,1,-1)

(0,15,Min,10)

Sample

EndTable

BeginProg

(15,Min,0,0)

(Depth_Ft,1,mV20,1,Vx1,1,5000,True

WtrData

NextScan

EndProg

6.4.2 BrFull6W Instruction (6-Wire Full Bridge Measurement)

'CR5000

'6 wire configuration

Public Depth_Ft

DataTable (WtrData,1,-1)

DataInterval

(1,Depth_Ft,FP2)

EndTable

BeginProg

(15,Min,0,0)

BrFull6W

CallTable

NextScan

EndProg

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CS420-L and CS425-L Pressure Transducers

7. Edlog Program Examples

7.1 CR10(X), CR510, and CR500 Examples

7.1.1 Instruction 6 (4-Wire Full Bridge Measurement)

7.1.1.1 Wiring

Datalogger CS420-L/CS425-L

Excitation

Input

E1

H1

Red (Supply +)

Yellow (Output +)

Input L1 Blue (Output -)

An. Ground AG White (Supply -)

The orange and black wires are not used and the ends of these wires should be taped to prevent shorting.

7.1.1.2 Edlog Program

; Measure one 4-wire DRUCK Sensor.

* Table 1 Program

01: 5

1: Full Bridge (P6)

1: 1

2: 3

Reps

25 mV slow range

3: 1

4: 1 Excite all reps w/Exchan 1

5: 2500 mV

6: 1 [DEPTH_FT]

7: 2.3529 Mult

8: -0.49 Offset

; Every 60 minutes output the array ID, time,

; and average water depth in feet

2: If Time Is (P92)

1: 0 Minutes (seconds --) into

2: 60

3: 10

1: 110

Interval (same units as above)

Set output flag high (Flag 0)

3: Real Time (P77)

Day, Hour/Minute (midnight = 0000)

4: Average (P71)

1: 1 Reps

2: 1

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CS420-L and CS425-L Pressure Transducers

7.1.2 Instruction 9 (6-Wire Full Bridge w/Excitation)

7.1.2.1 Wiring

Datalogger CS420-L/CS425-L

Excitation

Input

Input

E1

H1

L1

Red (Supply +)

Orange (Monitor +)

Black (Monitor -)

Input

Input

H2

L2

Yellow (Output +)

Blue (Output -)

An. Ground AG White (Supply -)

G

7.1.2.2 Edlog Program

; Measure one 6-wire DRUCK Sensor.

* Table 1 Programs

01: 5

1: Full Bridge w/mV Excit (P9)

1: 1 Reps

2: 5

3: 3

4: 1

5: 1

2500 mV Slow Ex Range

25 mV Slow Br Range

Excite all reps w/Exchan 1

6: 2500 mV

7: 1 Loc [DEPTH_FT]

8: 2.3529 Mult

9: -0.49 Offset

; Every 60 minutes output the array ID, time,

; and average water depth in feet

2: If time is (P92)

1: 0000

2: 60

3: 10

Minutes (seconds --) into a

Interval (same units as above)

Set output flag high (Flag 0)

3: Real Time (P77)

1: 110 Day, Hour/Minute (midnight = 0000)

4: Average (P71)

1: 1 Reps

2: 1

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CS420-L and CS425-L Pressure Transducers

7.2 CR23X and 21X Examples

7.2.1 Instruction 6 (4-Wire Full Bridge Measurement)

7.2.1.1 Wiring

Datalogger

Excitation

Input

Input

E1

H1

L1

G

CS420-L/CS425-L

Red (Supply +)

Yellow (Output +)

Blue (Output -)

White (Supply -)

The orange and black wires are not used and the ends of these wires should be taped to prevent shorting.

7.2.1.2 Edlog Program

; Measure one 4-wire DRUCK Sensor.

* Table 1 Program

01: 5

1: Full Bridge (P6)

1: 1

2: 22*

Reps

50 mV, 60 Hz Rejection, Slow Range

3: 1

4: 1 Excite all reps w/Exchan 1

5: 5000 mV

6: 1

7: 2.3529 Mult

8: -0.49 Offset

*for 21X use Range Code 3

; Every 60 minutes output the array ID, time,

; and average water depth in feet.

2: If time is (P92)

1: 0000 Minutes

2: 60

3: 10 Set output flag high

3: Real Time (P77)

1: 110 Day, Hour/Minute (midnight = 0000)

4: Average (P71)

1: 1

2: 1

Reps

[DEPTH_FT]

13

CS420-L and CS425-L Pressure Transducers

7.2.2 Instruction 9 (6-Wire Full Bridge w/Excitation)

7.2.2.1 Wiring

Datalogger CS420-L/CS425-L

Excitation

Input

Input

E1

H1

L1

Red (Supply +)

Orange (Monitor +)

Black (Monitor -)

Input

Input

H2

L2

Yellow (Output +)

Blue (Output -)

G White (Supply -)

G

7.2.2.2 Edlog Program

; Measure one 6-wire DRUCK Sensor.

* Table 1 Program

01: 5

1: Full Bridge w/mV Excit (P9)

1: 1 Reps

2 25*

3: 22**

4: 1

5: 1

5000 mV, 60Hz Rejection, slow Ex Range

50 mV, 60 Hz Rejection, Slow Br Range

Excite all reps w/Exchan 1

6: 5000 mV

7: 1

2.3529 Mult

9: -0.49 Offset

*For 21X use Range Code 5

**For 21X use Range Code 3

; Every 60 minutes output the array ID, time,

; and average water depth in feet

2: If time is (P92)

1: 0000 Minutes

2: 60 Minute a

Interval

3: 10 Set output flag high

3: Real Time (P77)

1: 110 Day, Hour/Minute (midnight = 0000)

4: Average (P71)

1: 1 Reps

2 1

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CS420-L and CS425-L Pressure Transducers

8. Using Multiplexers

Multiplexers increase the number of transducers a single datalogger can measure.

NOTE The CR500 and CR510 dataloggers do not support the use of multiplexers.

8.1 Examples

The dataloggers in the examples measure four Druck pressure transducers that are connected to an AM16/32A multiplexer. Excitation is supplied to the sensor from the datalogger wiring panel. In the examples, excitation voltage and ground connection to the sensor bypass the multiplexer and are applied directly from the datalogger to the sensor.

This configuration allows up to 16 pressure transducers to be measured using a single datalogger. Because the 5000 mV excitation exceeds the 21X’s drive current, the 21X requires two loops that measure eight sensors each.

NOTE These examples require a pressure transducer with a minimum impedance of 2K. Most Druck pressure transducers meet this requirement. However, you can verify the transducer’s impedance by reading across the red and white wire with an ohm meter.

8.1.1 Wiring For One Druck Multiplexer/Datalogger

Multiplexer CS420-L/CS425-L

SENSOR #1:

H1 (1)

L1 (1)

H2 (1)

L2 (1)

Orange (Monitor +)

Black (Monitor -)

Yellow (Output +)

Blue (Output -)

Shield Clear

Red (Excitation Voltage)

White (Supply G.)

Datalogger

E1

AG

Sensors #2, #3, and #4 are wired similarly to the multiplexer in sequential input terminals. All red and white sensor wires bypass the multiplexer and connect to the datalogger’s E1 and G respectively.

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CS420-L and CS425-L Pressure Transducers

8.1.2 Multiplexer Connection

Multiplexer Datalogger

COM H1 H1

COM L1 L1

COM H2 H2

COM L2 L2

12V 12V

G G

RES C1

CLK C2

Shield G

8.1.3 CRBasic Multiplexer Examples

8.1.3.1 CR800, CR850, and CR1000 Program

Although the following program was written for the CR1000, the CR800 and

CR850 could use the same program.

'CR1000

'For use with an AM16/32 in a 6 wire configuration, with four sensors.

Public WellDepth(4)

Dim LoopCount

Dim Mult(4)

Dim Offset(4)

DataTable (WellData,1,-1)

(0,30,Sec,10)

(4,WellDepth(),FP2)

(4,WellDepth(),FP2,False,True)

Minimum

EndTable

BeginProg

'Load multiplier and offset for each individual sensor

=

Mult(2)

=

Mult(4)

Offset(1)

=

Offset(3)

16

CS420-L and CS425-L Pressure Transducers

PortSet (1 ,1 )' Activate AM16/32

LoopCount = 1 'Reset loop counter

(0,Sec,4)

(2

Vx1,1,

2500,True,True,0,250,Mult(LoopCount),Offset(LoopCount))

LoopCount = LoopCount + 1

NextSubScan

PortSet (1 ,0)' Deactivate AM16/32

CallTable

NextScan

EndProg

8.1.3.2 CR3000 Program

'CR3000

'For use with an AM16/32 in a 6 wire configuration, with four sensors.

Public WellDepth(4)

Dim LoopCount

Dim Mult(4)

Dim Offset(4)

DataTable (WellData,1,-1)

DataInterval

(4,WellDepth(),FP2)

Minimum

EndTable

BeginProg

Scan

'Load multiplier and offset for each individual sensor

Mult(1)

=

Mult(4)

Offset(1)

=

Offset(3)

Offset(4)

PortSet (1 ,1 )' Activate AM16/32

LoopCount = 1 'Reset loop counter

PulsePort

17

CS420-L and CS425-L Pressure Transducers

'Switch to next transducer, delay 10000 use before measurement

BrFull6W(WellDepth(LoopCount),1,mv5000,mV50,1,Vx1,

,True,0,250,Mult(LoopCount),Offset(LoopCount))

LoopCount = LoopCount + 1

NextSubScan

PortSet (1 ,0)' Deactivate AM16/32

WellData

NextScan

EndProg

8.1.3.3 CR5000 Program

'CR5000

'For use with an AM16/32 in a 6 wire configuration, with four sensors.

Public WellDepth(4)

Dim LoopCount

Dim Mult(4)

Dim Offset(4)

DataTable (WellData,1,-1)

(0,30,Sec,10)

(4,WellDepth(),FP2)

(4,WellDepth(),FP2,False,True)

Minimum

EndTable

BeginProg

(5,Sec,0,0)

'Load multiplier and offset for each individual sensor

=

Mult(2)

=

Mult(4)

=

Offset(2)

=

Offset(4)

PortSet (1 ,1 )

LoopCount = 1

(0,Sec,4)

'Activate AM16/32

'Reset loop counter

(2

Delay

PortSet(2,0)

'Turn Control Port 2 on

'Turn Control Port 2 off -- this sequence

'provides a short 5V pulse that advances the to next

BrFull6W(WellDepth(LoopCount),1,mV5000,mV50,1,Vx1,1,

5000,True,True,0,250,Mult(LoopCount),Offset(LoopCount))

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CS420-L and CS425-L Pressure Transducers

LoopCount = LoopCount + 1

NextSubScan

PortSet (1 ,0)' Deactivate AM16/32

NextScan

EndProg

8.1.4 Edlog Example

The following program is for the CR10(X); a CR23X is programmed similarly.

NOTE Each sensor has an independent multiplier and offset that must be applied. To determine multiplier (M) and offset, see the

Multiplier and Offset sections.

* Table 1 Program

01: 60

; Set Reset on AM16/32A Multiplexer:

1: Do (P86)

1: 41 Set Port 1 High

2: Beginning of Loop (P87)

1: 0000 Delay

2: 4

3: Do (P86)

1: 72Pulse Port 2

4: Excitation with Delay (P22)

1: 1

2: 0

3: 1

Channel

Delay w/Ex (units = 0.01 sec)

Delay after Ex (units = 0.01 sec)

4: 0

; Measure Druck Pressure Transducer

5: Full Bridge w/mV Excit (P9)

1: 1

2: 5

Rep

2500 mV Slow Ex Range

3: 3

4: 1

5: 1

25 mV Slow Br Range

DIFF

Excite all reps w/Exchan 1

6: 2500 mV

7: 1--

8: 1

9: 0

Loc [DEPTH_FT] (--Index Input Loc.1-4)

Mult

Offset

19

CS420-L and CS425-L Pressure Transducers

6: End (P95)

; Deactivate Multiplexer

7: Do (P86)

1: 51 Set Port 1 Low

; Adjust sensor readings for multiplier and

; offset:

8: Scaling Array (A*Loc + B) (P53)

1: 1

;Multiplier

3: .36781 B1

;Multiplier

5: .4011 B2

7: .2103 B3

8: 1.9821 A4

#3

#4

;Offset

; Record average depth every hour.

9: If Time is (P92)

1: 0000

2: 60

3: 10

Minutes (seconds --) into a

Minute Interval (same units as above)

Set output flag high (Flag 0)

10: Real Time (P77)

1: 110

11: Average (P71)

1: 4 Reps

2: 1

9. Maintenance

Periodic evaluation of the desiccant is vital for keeping the vent tube dry. To assess the effectiveness of the desiccant, use one of the following:

• An indicating desiccant that changes color when it’s losing its drying power

• An enclosure humidity indicator such as our #6571 humidity indicator card

9.1 Every Visit, At Least Monthly

• Collect data

• Visually inspect wiring and physical conditions

20

CS420-L and CS425-L Pressure Transducers

NOTE

• Check indicating desiccant or enclosure humidity indicator; service desiccant if necessary

• Check battery condition (inspect physical appearance and use a keyboard display or laptop to view the battery voltage)

• Check all sensor readings (using keyboard display or laptop); adjust transducer offsets if necessary

• Check recent data using keyboard display or laptop

• Perform routine maintenance suggested by manufacturers

See datalogger manual for more information about using a keyboard display or laptop to view battery voltage, sensor readings, and recent data.

9.2 Every Three Months

• Change batteries (as needed--may be less often)

• Replace enclosure desiccants

• Check calibration of all sensors

• Inspect probe cable conditions for deterioration or damage

• Check wire connections ensuring they are still secure

9.3 Every Two to Three Years or on a Rotating Schedule

Send the transducers to the factory or laboratory for inspection and have them serviced and/or replaced as needed.

10. Troubleshooting

The most common causes of erroneous pressure transducer data include:

• poor sensor connections to the datalogger

• damaged cables

• damaged transducers

• moisture in the vent tube

21

CS420-L and CS425-L Pressure Transducers

To troubleshoot, do the following:

• Check your connections to the datalogger. Look for loose or broken wires, and moisture at the points of connection.

• Inspect the pressure transducer cable for wear, stress, or other indications of damage.

• Check the vent tube for plugging and condensation.

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