CS526 ISFET pH Probe 2/12 C o p y r i g h t © 2 0 0 9 - 2 0 1 2 C a m p b e l l S c i e n t i f i c , I n c .
Warranty The CS526 ISFET pH Probe is warranted for six (6) months subject to this limited warranty: “PRODUCTS MANUFACTURED BY CAMPBELL SCIENTIFIC, INC. are warranted by Campbell Scientific, Inc. (“Campbell”) to be free from defects in materials and workmanship under normal use and service for twelve (12) months from date of shipment unless otherwise specified in the corresponding Campbell pricelist or product manual.
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.
CS526 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 2. Cautionary Statements................................................1 3. Initial Inspection ..........................................................1 4. Quickstart .....................................................................2 5. Overview........
CS526 Table of Contents Appendix A. Calibration................................................................ A-1 Figure 11-1. Tip of the CS526 Probe ...................................................................... 10 Tables 7-1. 8-1. 8-2. 9-1. CR800, CR850, CR1000, and CR3000 Wiring...................................... 4 Get Data Command and Response ......................................................... 5 Instruction Sequence..................................................................
CS526 ISFET pH Probe 1. Introduction The CS526 ISFET pH Probe measures pH from 0 to 14 in aqueous or semisolid solutions. It outputs TTL serial data that is read by compatible dataloggers (see Section 6 Specifications). Before using the CS526, please study • Section 2. Cautionary Statements • Section 3. Initial Inspection • Section 4. Quickstart More detailed instructions for operation, troubleshooting, and maintenance are available in the remaining sections. 2.
CS526 ISFET pH Probe 4. Quickstart For complete installation, programming, and calibration information, see Sections 7 through 9. The CS526 is shipped dry. Before the probe can be calibrated, it must be soaked in 7 pH buffer solution for 15 minutes. Follow the calibration procedure outlined in Appendix A. Unlike many glass-bulb type pH sensors, the CS526 ISFET pH probe can be installed without regard to orientation. Connect the CS526 to the datalogger according to the following table.
CS526 ISFET pH Probe 5. Overview The submersible CS526 is designed to reliably provide accurate temperature compensated pH measurements. The pH-sensitive element is SENTRON's Ion Sensitive Field Effect Transistor (ISFET) semi-conductor, which includes a silver / silver chloride - potassium chloride reference system. This technology is the most significant breakthrough in pH testing in half a century and is the most powerful pH testing technology available today.
CS526 ISFET pH Probe Maximum Cable Length: 100 m (328 ft) Cable Type: Three-twisted pair, 24 awg cable with Santoprene® jacket Sensor Material: PEEK Weight w/10 ft Cable: Dimensions Length: Diameter: 318 g (11.2 oz) 102 mm (4 in) 16 mm (0.63 in) Certifications: ISO 9001 compliant EMC standard IEC61326:2005 7. Installation and Wiring 7.1 Preparation for Use The CS526 is shipped dry. Before the probe can be calibrated, soak it in 7 pH buffer solution for 15 minutes.
CS526 ISFET pH Probe instruction (see Section 8.2.2.2). Table 8-1 shows the “get data” command and its response. TABLE 8-1. Get Data Command and Response Command Response aMn! a Where: a = probe address (factory default is 1) n = a single dummy character (typically use 1) Where: a = probe address (factory default is 1) = the probe’s reading for pH (in millivolts). 8.2 CRBasic Programming 8.2.
CS526 ISFET pH Probe 8.2.2 Instruction Descriptions 8.2.2.1 SerialOpen() Instruction The SerialOpen() instruction has the following syntax: SerialOpen(ComPort,BaudRate,Format,TXDelay,BufferSize) ComPort — the datalogger COM port to which the probe is connected. BaudRate — choose 2400 Format — choose 16, which is TTL Logic; No parity, one stop bit, 8 data bits; No error checking TXDelay — enter 0 BufferSize — enter at least twice the number of maximum expected characters + 1, which is 41. 8.2.2.
CS526 ISFET pH Probe 8.2.2.4 SplitStr Instruction The SplitStr() instruction has the following syntax: SplitStr(SplitResult,SearchString,FilterString,NumSplit,SplitOption) SplitResult — an array in which the split string will be stored. SearchString — the string on which this instruction will operate. This will be the variable entered for the Dest parameter for the SerialIn instruction (see above). FilterString — enter “String” (this value will be ignored because of the SplitOption that will be used).
CS526 ISFET pH Probe TABLE 9-1. Calibration Standards pH CSI Part Number 4 25587 7 25586 10 25588 Frequency of calibration depends on the level of accuracy required and the coating / fouling nature of the measured samples. 10. Troubleshooting The most common causes for erroneous pH data include: • poor sensor connections to the datalogger • damaged cables • scratched chip Problem: Output signal is at its maximum value. Possible reason: o Probe is not in fluid. o Chip is polluted.
CS526 ISFET pH Probe 11. Maintenance Campbell Scientific recommends that the CS526 be cleaned and calibrated periodically to insure accurate readings. The CS526 has no user-serviceable parts. If the CS526 is not operating properly and requires return to Campbell Scientific, first obtain an RMA (returned material authorization) and fill out the Declaration of Hazardous Material and Decontamination form. This information is available at http://www.campbellsci.com/repair.
CS526 ISFET pH Probe Diaphragm Chip FIGURE 11-1.
Appendix A. Calibration This calibration process uses 7 pH and 4 pH buffer solutions. NOTEProtect the sensing chip from UV radiation during calibration. If calibrating in sun or fluorescent light, shield the sensing chip from UV by using dark containers for the buffer solutions. Load the following example CRBasic program into the datalogger. Wire the CS526 to the datalogger according to the following diagram.
Appendix A. Calibration Following is a simple example program to facilitate the two point calibration.
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