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CS547A-L
User Manual
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Campbell Scientific CS547A-L User Manual

CS547A Conductivity and
Temperature Probe and
A547 Interface
Revision: 10/11
Copyright © 1994-2011
Campbell Scientific, Inc.

Warranty

Assistance

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 (435) 227-2342. 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 "Statement of Product Cleanliness and Decontamination" form and comply with the requirements specified in it. The form is available from our web site at www.campbellsci.com/repair. A completed form must be either emailed to repair@campbellsci.com or faxed to (435) 227-9579. Campbell Scientific is unable to 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.
CS547A Probe and A547 Interface Table of Contents
PDF viewers: These page numbers refer to the printed version of this document. Use the PDF reader bookmarks tab for links to specific sections.
1. Overview.......................................................................1
1.1 EC Sensor .................................................................................................1
1.2 A547 Interface ..........................................................................................1
2. Specifications ..............................................................2
2.1 CS547A Probe ..........................................................................................2
2.2 A547 Interface ..........................................................................................2
2.3 Temperature Sensor..................................................................................3
3. Installation....................................................................3
3.1 Site Selection ............................................................................................3
3.2 Mounting ..................................................................................................3
4. Wiring............................................................................3
5. Programming ...............................................................4
5.1 Programming Overview............................................................................4
5.2 Example Measurement Programs .............................................................5
5.2.1 CRBasic ..........................................................................................5
5.2.2 Edlog...............................................................................................7
6. Calibration ..................................................................12
6.1 Conversion Factors .................................................................................12
6.2 Typical Ranges .......................................................................................12
6.3 Factory Calibration .................................................................................12
6.4 Field Calibration .....................................................................................12
6.4.1 CRBasic Calibration Program Example........................................13
6.4.2 Edlog Calibration Program Example ............................................13
7. Maintenance ...............................................................15
8. Analysis of Errors......................................................15
8.1 EC Measurement Error ...........................................................................15
8.2 Temperature Measurement Error............................................................17
9. Deriving a Temperature Compensation Coefficient ..... 18
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CS547A Probe and A547 Interface Table of Contents
10. Therm107 / P11 Instruction Details ........................18
11. Electrically Noisy Environments ............................20
12. Long Lead Lengths Temperature ...........................20
13. CS547A Schematic ..................................................21
Figures
1-1. A547 Interface and CS547A Conductivity and Temperature Probe ...... 2
4-1. CS547A wiring diagram for example below.......................................... 4
8.1-1. Plot of ideal and actual correction between 0 and 0.44 mS cm
8.1-2. Plot of ideal and actual correction between 0.44 and 7.0 mS cm
8.2-1. Error produced by polynomial fit to published values ...................... 17
13-1. CS547A Conductivity and Temperature circuit diagram ................... 21
13-2. A547 Interface circuit diagram........................................................... 22
-1
....... 16
-1
.... 16
Tables
8.2-1. Thermistor Interchangeability Specification Temperature ................ 17
8.2-2. Polynomial Error ............................................................................... 17
10-1. Temperature , Resistance, and Datalogger Output ............................. 19
10-2. Polynomial Coefficients ..................................................................... 19
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CS547A Conductivity and Temperature Probe and A547 Interface

1. Overview

The CS547A conductivity and temperature probe, and A547 interface are designed for measuring the electrical conductivity, dissolved solids, and temperature of fresh water with Campbell Scientific dataloggers. This sensor can be used with any CSI logger that can issue a negative excitation. This includes most new CRBasic dataloggers as well as older, Edlog loggers. Exceptions include the CR200-series, the BDR301 and BDR320 loggers which did not have this feature. Use with our AM16/32(B) multiplexer is possible when needing to measure several of these probes on one datalogger.
Electrical conductivity (EC) of a solution is a simple physical property, but measurements can be difficult to interpret. This manual instructs the user how to make EC measurements with the CS547A. Accuracy specifications apply to measurements of EC in water containing KCl, Na which are typical calibration compounds, and to EC not yet compensated for temperature effects.
Statements made on methods of temperature compensation or estimating dissolved solids are included to introduce common ways of refining and interpreting data, but are not definitive. Authoritative sources to consult include the USGS Water­Supply Paper 1473, The pH and Conductivity Handbook published by OMEGA Engineering, physical chemistry texts, and other sources.
, NaHCO3, and/or NaCl,
2SO4

1.1 EC Sensor

The EC sensor consists of three stainless steel rings mounted in an epoxy tube as shown in Figure 4-1. Resistance of water in the tube is measured by excitation of the center electrode with positive and negative voltage.
This electrode configuration eliminates the ground looping problems associated with sensors in electrical contact with earth ground.
Temperature is measured with a thermistor in a three wire half bridge configuration.

1.2 A547 Interface

The interface contains the completion resistors and blocking capacitors. The interface should be kept in a non-condensing environment that is maintained within the temperature range of the unit.
1
CS547A Conductivity and Temperature Probe and A547 Interface
FIGURE 1-1. A547 Interface and CS547A Conductivity and Temperature Probe

2. Specifications

2.1 CS547A Probe

Construction
Size — L x W x H
Minimum Pipe ID in which CS547A Fits
Maximum Cable Length
Depth Rating
pH Range
Electrodes
Cell Constant
Temp. Range of Use
EC Range
Accuracy
Weight with 4 ft Cable
The probe housing is epoxy
89 mm (3.5 in.) x 25.4 mm (1 in.) x 19 mm (0.75 in.)
28 mm (1.1 in.)
305 m (1000 ft). The sensor must be ordered with desired length as cable cannot be added to existing probes.
Maximum 305 m (1000 ft)
Solution pH of less than 3.0 or greater than 9.0 may damage the stainless steel housing.
Passivated 316 SS with DC isolation capacitors.
Individually calibrated. The cell constant (K on a label near the termination of the cable.
0° to 50°C.
Approx. 0.005 to 7.0 mS cm
in KCl and Na 25°C: ±5% of reading 0.44 to 7.0 mS cm ±10% of reading 0.005 to 0.44 mS cm
120 g (4.2 oz)
, NaHCO3, and NaCl standards at
2SO4
-1
.
-1
.
-1
.
) is found
c
2

2.2 A547 Interface

Size
Temperature Rating
Dimensions: 64 mm (2.5 in.) x 46 mm (1.8 in.) x 23 mm (0.9 in.) Weight: 45 g (2 oz)
-15° to +50°C
CS547A Conductivity and Temperature Probe and A547 Interface

2.3 Temperature Sensor

3. Installation

CAUTION

3.1 Site Selection

3.2 Mounting

Thermistor
Range
Accuracy
Rapid heating and cooling of the probe, such as leaving it in the sun and then submersing it in a cold stream, may cause irreparable damage.
The EC sensor measures the EC of water inside the hole running through the sensor, so detection of rapid changes in EC requires that the probe be flushed continuously. This is easy to accommodate in a flowing stream by simply orienting the sensor parallel to the direction of flow. In stilling wells and ground wells, however, diffusion rate of ions limits the response time.
The housing and sensor cable are made of water impervious, durable materials. Care should be taken, however, to mount the probe where contact with abrasives and moving objects will be avoided. Strain on cables can be minimized by using a split mesh strain relief sleeve on the cable, which is recommended for cables over 100 ft. The strain relief sleeve is available from Campbell Scientific as part number 7421.
Betatherm 100K6A1.
0° to 50°C.
Error ±0.4°C (See Section 8.2).

4. Wiring

WARNING
Because the CS547A has a slightly positive buoyancy, we recommend securing the sensor to a fixed or retractable object or selecting the cable weight option.
The A547 is usually mounted in the datalogger enclosure.
The voltage excitation channel used for each EC measurement must be separate from the one used for temperature or measurement errors will result. If multiple CS547A/A547s are to be wired to a single logger, each conductivity excitation must be kept on a separate, dedicated VX or EX channel, but you can combine several temperature excitations lines onto a single VX or EX port.
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