CS525 ISFET pH Probe Revision: 10/11 C o p y r i g h t © 2 0 0 9 - 2 0 1 1 C a m p b e l l S c i e n t i f i c , I n c .
WARRANTY AND ASSISTANCE This equipment is warranted by CAMPBELL SCIENTIFIC (CANADA) CORP. (“CSC”) 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 are not warranted. ***** CSC's obligation under this warranty is limited to repairing or replacing (at CSC's option) defective products. The customer shall assume all costs of removing, reinstalling, and shipping defective products to CSC.
PLEASE READ FIRST About this manual Please note that this manual was originally produced by Campbell Scientific Inc. (CSI) primarily for the US market. Some spellings, weights and measures may reflect this origin. Some useful conversion factors: Area: 1 in2 (square inch) = 645 mm2 Length: 1 in. (inch) = 25.4 mm 1 ft (foot) = 304.8 mm 1 yard = 0.914 m 1 mile = 1.609 km Mass: 1 oz. (ounce) = 28.35 g 1 lb (pound weight) = 0.454 kg Pressure: 1 psi (lb/in2) = 68.95 mb Volume: 1 US gallon = 3.
CS525 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. Introduction..................................................................1 1.1 Initial Inspection and Handling Guidelines ..............................................2 2. Specifications ..............................................................2 3. Installation and Wiring ................................................3 3.
CS525 ISFET pH Probe The CS525 probe is designed for general pH measurements in aqueous or semi-solid solutions. It provides a 0 to 5 Vdc output that represents a 0 to 14 pH range. CAUTION The CS525-L ISFET pH Sensor is highly susceptible to ground looping and galvanic conditions. In many cases this can be isolated by NOT grounding the datalogger to an earth ground. However, the most successful isolation technique to overcome these issues is to use the CWS900 Wireless Sensor Interface.
CS525 ISFET pH Probe connected in the correct way to the datalogger. Any other combinations might cause a loss of performance and irreversible damage to both probe and/or datalogger. 1.1 Initial Inspection and Handling Guidelines Upon receipt of the CS525, 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.
CS525 ISFET pH Probe 3. Installation and Wiring NOTE Campbell Scientific only offered the 0 to 5000 mV output range for CS525 probes ordered before January 2010. These probes had four wires instead of five. Wire colors were red (signal), black (power), white (signal reference), and clear (shield). 3.1 Preparation for Use The CS525 is shipped dry. Before the probe can be calibrated, soak it in 7 pH buffer solution for 15 minutes.
CS525 ISFET pH Probe TABLE 3-2. CR200(X) Series Wiring Wire Color Wire Label/Function VDIV2:1* Red Power 5 Vdc Black Signal Reference G White Signal H Clear Shield CR200(X) Series EX SE G *When using the VDIV2:1 with the CR200(X)-series datalogger, the L peg of the VDIV2:1 is not used and can be removed. 4. Programming 4.1 Using SCWIN for CR800, CR850, CR1000, and CR3000 In SCWIN, the CS525 is programmed by selecting single-ended voltage under Generic Measurements.
CS525 ISFET pH Probe ‘CR200(X) Series ‘Declare the variable for the pH measurement Public pHmV ‘Read sensor every 60 seconds BeginProg Scan(60,sec) ‘Turn power on, delay for 30000 microseconds, then measure sensor ExDelSE(pHmV,1,1,Ex1,mV5000,30000,1,0.0) NextScan EndProg 4.2.1.2 CR800, CR850, CR1000, and CR3000 Programming For the CR800, CR1000 and CR3000 dataloggers, Instruction VoltSe is used to read Single-ended analog sensors. A multiplier of 1.0 and an offset of 0.0 yields millivolts.
CS525 ISFET pH Probe Below is an example program for CR800, CR850, CR1000, and CR3000 dataloggers when the sensor has a ±400 mV output (see Note below). ‘CR1000 Series Datalogger ‘Declare the variable for the pH measurement Public pHmV ‘Read sensor every 60 seconds BeginProg Scan(60,sec,1,0) ‘Code for VoltSE measurements: VoltSE(pHmV,1, mV250,1,False,0,_60Hz,1,0) NextScan EndProg NOTE The mV250 range option may be inadequate for pH ranges that are greater than 11 or less than 2.
CS525 ISFET pH Probe The CS525 has no user-serviceable parts. Cable can be damaged by abrasion, rodents, sharp objects, twisting, crimping or crushing and pulling. Take care during installation and use to avoid cable damage. 6.1 Cleaning It is possible that contamination on the diaphragm will block the built-in reference electrode. In that case there will be no electrical contact between the electrode and the ISFET chip and the probe will not function. To prevent this, regular cleaning is recommended.
CS525 ISFET pH Probe 7. Troubleshooting The most common causes for erroneous pH data include: x x x poor sensor connections to the datalogger damaged cables scratched chip Problem: Output signal is at its maximum value. Possible reason: x x x x Probe is not in fluid. Chip is polluted. Diaphragm is polluted. Chip is scratched. Suggestion: x x x Put probe in fluid. Clean probe using soapy water method. Probe can not be fixed if chip is scratched. Problem: Probe response is very slow.
Appendix A. Calibration This calibration process uses a 7 pH and 4 pH buffer solution (CSI part number). After downloading the following example program onto the datalogger, and insuring that the CS525 is properly wired to the datalogger, the operator would use the Numeric Display found in the software PC200W, PC400, LoggerNet, PConnect, and PConnectCE, to: 1. Place the CS525 into a pH 7 buffer solution (CSI PN 25586). 2. Allow the pHmV reading to stabilize. 3. Change the value in pH7record to -1. 4.
Appendix A.
Campbell Scientific Companies Campbell Scientific, Inc. (CSI) 815 West 1800 North Logan, Utah 84321 UNITED STATES www.campbellsci.com • info@campbellsci.com Campbell Scientific Africa Pty. Ltd. (CSAf) PO Box 2450 Somerset West 7129 SOUTH AFRICA www.csafrica.co.za • cleroux@csafrica.co.za Campbell Scientific Australia Pty. Ltd. (CSA) PO Box 444 Thuringowa Central QLD 4812 AUSTRALIA www.campbellsci.com.au • info@campbellsci.com.au Campbell Scientific do Brazil Ltda.
