Campbell Scientific CS431 User Manual

CS431 Submersible

Pressure Transducer

Revision: 3/09

Copyright © 2008-2009

Campbell Scientific, Inc.

Warranty and Assistance

The CS431 SUBMERSIBLE PRESSURE TRANSDUCER is warranted by
CAMPBELL SCIENTIFIC, INC. to be free from defects in materials and
workmanship under normal use and service for twelve (12) months from date
of shipment unless specified otherwise. Batteries have no warranty.
CAMPBELL SCIENTIFIC, INC.'s obligation under this warranty is limited to
repairing or replacing (at CAMPBELL SCIENTIFIC, INC.'s option) defective
products. The customer shall assume all costs of removing, reinstalling, and
shipping defective products to CAMPBELL SCIENTIFIC, INC. CAMPBELL
SCIENTIFIC, INC. will return such products by surface carrier prepaid. This
warranty shall not apply to any CAMPBELL SCIENTIFIC, INC. products
which have been subjected to modification, misuse, neglect, accidents of
nature, or shipping damage. This warranty is in lieu of all other warranties,
expressed or implied, including warranties of merchantability or fitness for a
particular purpose. CAMPBELL SCIENTIFIC, INC. is not liable for special,
indirect, incidental, or consequential damages.

Products may not be returned without prior authorization. The following
contact information is for US and International customers residing in countries
served by Campbell Scientific, Inc. directly. Affiliate companies handle
repairs for customers within their territories. Please visit
www.campbellsci.com to determine which Campbell Scientific company
serves your country.

To obtain a Returned Materials Authorization (RMA), contact CAMPBELL
SCIENTIFIC, INC., phone [phone]. After an applications engineer
determines the nature of the problem, an RMA number will be issued. Please
write this number clearly on the outside of the shipping container.
CAMPBELL SCIENTIFIC's shipping address is:

CAMPBELL SCIENTIFIC, INC.

RMA#_____
815 West 1800 North
Logan, Utah 84321-1784

For all returns, the customer must fill out a “Declaration of Hazardous Material
and Decontamination” form and comply with the requirements specified in it.
The form is available from our website at
completed form must be either emailed to [e-mail]
to 435-750-9579. Campbell Scientific will not process any returns until we
receive this form. If the form is not received within three days of product
receipt or is incomplete, the product will be returned to the customer at the
customer’s expense. Campbell Scientific reserves the right to refuse service on
products that were exposed to contaminants that may cause health or safety
concerns for our employees.

www.campbellsci.com/repair

. A

or faxed

CAMPBELL SCIENTIFIC, INC. does not accept collect calls.

CS431 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 Description.....................................................1

2. Specifications ..............................................................1

3. Installation....................................................................2

3.1 Initial Inspection.......................................................................................2

3.2 Vent Tube.................................................................................................2

3.3 Water Depth..............................................................................................2

3.4 Well Installations......................................................................................2

3.5 Other Installations.....................................................................................3

4. Wiring............................................................................3

4.1 Datalogger Connections............................................................................3

4.2 Grounding.................................................................................................4

5. Datalogger Programming............................................4

5.1 CRBasic Instructions................................................................................5

5.1.1 Example CRBasic Programs...........................................................6

5.1.1.1 Example CR1000 PROGRAM – STANDARD

CALIBRATION.................................................................6

5.1.1.2 Example CR1000 PROGRAM – ENHANCED

CALIBRATION.................................................................8

5.2 Edlog Instructions.....................................................................................9

5.2.1 Example Edlog Programs..............................................................10

5.2.1.1 Example CR10X PROGRAM – STANDARD...................10

5.2.1.2 Example CR10X PROGRAM – Enhanced Measurement ..11

5.2.1.3 Example CR10X PROGRAM – High Precision

Measurement for 5 PSI Sensors.......................................12

6. Maintenance...............................................................13

7. Troubleshooting ........................................................14

7.1 Erratic Readings .....................................................................................14

7.2 Oscillating Readings Over Time.............................................................14

7.3 Zero Readings When Pressurized...........................................................14

7.4 Grounding Issues....................................................................................14

i

CS431 Table of Contents

Figures

Tables

4.1. Typical Pressure Element Wiring .......................................................... 3

4-2. Typical Temperature Element Wiring.................................................... 4

6-1. Desiccant Tube..................................................................................... 13

5-1. CR1000 Connections for Example Programs......................................... 6

ii

CS431 Submersible Pressure Transducer

1. General Description

The CS431 PS9805 Pressure Transducer is manufactured by Instrumentation
Northwest for use with Campbell Scientific dataloggers. It uses piezoresistive
strain gage technology to measure water level and an on-board thermistor to
measure temperature. Piezoresistive transducers include a strain gage bonded
to a pressure-sensitive diaphragm. Electrical resistance changes as pressure
changes on the diaphragm. Campbell Scientific dataloggers measure the
resistance then convert the measured value to the desired units. The CS431 is
compatible with most of our dataloggers (see datalogger compatibility in
specifications).

The CS431 has a 316 stainless steel body and Viton® and Teflon® wire seals
that resist corrosion. Its double-sealed cable harness protects the cable jacket
and reduces the possibility of leakage. The end cone is interchangeable with a
¼" NPT inlet allowing easy hookup and field calibration. You can choose a
polyurethane or Teflon cable. Both cable options are vented. An optional
enhanced measurement calibration is available that allows more accurate
compensation for temperature variations.

2. Specifications

Datalogger Compatibility: All except CR200 series; the CR500 and CR510

Available Pressure Ranges: 5, 10, 30, 50, 100 psi
Pressure Measurement Repeatability: ±0.1% FSO, typical
Pressure Measurement Linearity: ±0.1% FSO, typical
Temperature Error: ±2.0% FSO, 0° to 40°C
Temperature Error when using Enhanced Temperature option: ±0.2% FSO,

Typical Output Voltage Sensitivity: 15 to 16 mV/V at 20°C
Typical Bridge Resistance: 4 kohm at 20°C
Typical Excitation Voltage: 0.8 V
Compensated Temperature Range: 0° to 40°C
Operating Temperature Range: -5° to 70°C
Maximum Cable Length: 2000 ft
Dimensions: 0.84" (2.13 cm) diameter, 10.75" (27.31 cm) length
Weight: 3 lbs (1.4 kg) with 50 ft cable
Over Range Protection: 2X full scale range

can measure water level only.

0° to 40°C

1

CS431 Submersible Pressure Transducer

3. Installation

3.1 Initial Inspection

Upon receipt of the CS431, inspect the packaging for any signs of shipping
damage and, if found, report the damage to the carrier in accordance with
policy. The contents of the package should also be inspected and a claim filed
if any shipping related damage is discovered.

Care should be taken when opening the package not to damage or cut the cable
jacket. If there is any question about damage having been caused to the cable
jacket, a thorough inspection is prudent.

The model number and pressure range is etched on the housing. Check this
information against the shipping documentation to ensure that the expected
model number and range were received.

3.2 Vent Tube

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

To prevent water vapor from entering the inner cavity of the sensor, the vent
tube opening should terminate inside a desiccated enclosure or a desiccant
tube.

3.3 Water Depth

For water level measurements, the CS431 must be installed below the water at
a fixed depth. This depth should be chosen so that the water pressure will
never exceed the sensor’s pressure range. Otherwise, the output reading will
not be correct, and can be damaged if pressure is excessive (2X full scale).

Pressure can be converted to feet of fresh water using the following equation:
1 psi = 2.31 feet of water
For example, the maximum depth with a pressure range of 0 to 5 psi is 11.55

feet of water.

3.4 Well Installations

Lower the transducer to an appropriate depth.

CAUTION

Do not drop the instrument or allow it to “free fall” down a
well as this may damage the device.

Fasten the cable to the well head using cable ties or a weather proof strain­relief system (i.e., split mesh cable grip p/n 7421). The cable ties should wrap
around the cable jacket; never suspend the CS431 from the connections at the
top end of the cable. When securing the cable, care should be taken to avoid
cable damage. Sharp bends or excessive pinching of the cable can cause
damage and may pinch off the vent tube causing measurement errors.

2

Several readings should be taken to insure proper operation after installation.

3.5 Other Installations

4. Wiring

4.1 Datalogger Connections

CS431 Submersible Pressure Transducer

The CS431 can be installed in any position; however, when it leaves the
factory it is tested in the vertical position. Strapping the transducer body with
tie wraps or tape will not hurt it.

If the CS431 is being installed in a fluid environment other than water, check
the compatibility of the fluid with the wetted parts of the probe.

Because the CS431 is vented, a desiccant tube must always be attached to the
CS431. When you receive the transducer, ensure that the desiccant is blue.
Replace the desiccant if it is pink or white. Refer to Section 6 for more
information about desiccant replacement schedule.

The pressure measurement requires two differential channels and one
excitation channel, and the temperature measurement requires one single-ended
channel and one excitation channel. Please note that the CR510 and CR500
dataloggers do not have enough channels to measure the temperatur e element.
Therefore, the orange, brown, and black wire s are not conne c t ed whe n usi n g a
CR510 or CR500.

FIGURE 4.1. Typical Pressure Element Wiring

3