Campbell CS526 User manual

CS526 ISFET pH Probe
Revision: 6/13
Copyright © 2009-2013
Campbell Scientific, Inc.

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. Products not manufactured, but that are
re-sold by Campbell, are warranted only to the limits extended by the original
manufacturer. Batteries, fine-wire thermocouples, desiccant, and other
consumables have no warranty. Campbell's obligation under this warranty is
limited to repairing or replacing (at Campbell's option) defective products,
which shall be the sole and exclusive remedy under this warranty. The
customer shall assume all costs of removing, reinstalling, and shipping
defective products to Campbell. Campbell will return such products by surface
carrier prepaid within the continental United States of America. To all other
locations, Campbell will return such products best way CIP (Port of Entry)
INCOTERM® 2010, prepaid. This warranty shall not apply to any products
which have been subjected to modification, misuse, neglect, improper service,
accidents of nature, or shipping damage. This warranty is in lieu of all other
warranties, expressed or implied. The warranty for installation services
performed by Campbell such as programming to customer specifications,
electrical connections to products manufactured by Campbell, and product
specific training, is part of Campbell’s product warranty. CAMPBELL
EXPRESSLY DISCLAIMS AND EXCLUDES ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A
PARTICULAR PURPOSE. Campbell is not liable for any special, indirect,
incidental, and/or consequential damages.”

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 [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 "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 [e-mail] or faxed to
[phone]. 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.

Table of Contents
PDF viewers: These page numbers refer to the printed version of this document. Use the
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1. Introduction.................................................................1
2. Cautionary Statements...............................................1
3. Initial Inspection .........................................................2
4. Quickstart ....................................................................2
5. Overview......................................................................3
6. Specifications .............................................................3
7. Installation and Wiring ...............................................4
7.1 Preparation for Use ..............................................................................4
7.2 Wiring ..................................................................................................4
8. Programming ..............................................................5
8.1 Get Data Command..............................................................................5
8.2 CRBasic Programming.........................................................................5
8.2.1 Instruction Sequence.....................................................................5
8.2.2 Instruction Descriptions ................................................................6
8.2.2.1 SerialOpen() Instruction.....................................................6
8.2.2.2 SerialOut() Instruction........................................................6
8.2.2.3 SerialIn() Instruction ..........................................................6
8.2.2.4 SplitStr() Instruction...........................................................7
8.2.3 Example Program..........................................................................7
8.2.4 Programming for Calibration ........................................................7
9. Calibration ...................................................................8
10. Troubleshooting..........................................................8
11. Maintenance ................................................................9
11.1 Cleaning ...............................................................................................9
11.1.1 When to Clean...............................................................................9
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Table of Contents
ii
11.1.2 Cleaning Procedure .................................................................... 10
11.1.2.1 Cleaning Tips................................................................... 10
11.1.3 Revitalizing ................................................................................ 11
11.2 Storage............................................................................................... 11
11.2.1 Short-Term Storage (2 days or less)........................................... 11
11.2.2 Long-Term Storage (more than 2 days) ..................................... 11
Appendix
A. Calibration ...............................................................A-1
A.1 Example Calibration Program ......................................................... A-2
Figures
11-1. Tip of the CS526 probe ..................................................................... 10
Tables
7-1. CR800, CR850, CR1000, and CR3000 Wiring................................... 4
8-1. “Get Data” Command and Response................................................... 5
8-2. Instruction Sequence ........................................................................... 5
9-1. Calibration Standards .......................................................................... 8

CS526 ISFET pH Probe
1. Introduction
The CS526 ISFET pH Probe measures pH from 1 to 14 in aqueous or semi-
solid 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. Cautionary Statements
•Campbell Scientific warranty does not cover a clogged reference diaphragm or
improperly cleaned or maintained ISFET chip (see Section 11, Maintenance).
•Maximum input voltage is 5 Vdc. Incorrect wiring may cause performance
loss and irreversible damage.
•To prevent scratching the sensor chip when cleaning, first soak the sensor in
soapy water and then gently scrub with a toothbrush (see Section 11,
Maintenance). Most scratches occur when hard particles are rubbed on the
chip surface. Scratches cause irreversible damage to the probe.
•Do not use hydrofluoric acid, acetone, MEK, or similar agents to clean the
probe.
•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.
•The CS526 is rugged, but it should be handled as a precision scientific
instrument.
•The CS526 has no user-serviceable parts. Any attempt to disassemble the
device will void the six-month warranty.
•Care should be taken when opening the shipping package to not damage or cut
the cable jacket. If damage to the cable is suspected, consult with a Campbell
Scientific applications engineer.
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CS526 ISFET pH Probe
3. Initial Inspection
Upon receipt of the CS526, inspect the packaging and contents for damage.
File damage claims with the shipping company.
The model number and cable length are printed on a label at the connection end
of the cable. Check this information against the shipping documents to ensure
the correct product and cable length are received.
4. Quickstart
For complete installation, programming, and calibration information, see
Sections 7through 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, Calibration.
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. Be sure to connect Red to the 5V channel.
Wire Color Datalogger Connection
Red (Caution! 5 Vdc max!) 5V
Black G
White Control Port (Tx)
Green Control Port (Rx)
Clear G
Program the datalogger as follows.
'CR1000 Series Datalogger
'Declare variable for digital pH measurement
Public pHCount
'Declare variables for serial input from sensor
Dim rawstring As String * 20, pHDigit(2)
'Main Program
BeginProg
'Set up datalogger port for serial communication
SerialOpen ( Com1,2400,16,0,41)
'Establish program scan rate of 60 seconds
Scan (60,Sec,0,0)
'Send get data command to CS526
SerialOut (Com1,"1M1!"&CHR(13),"",0,0)
'Set up COM1 to receive incoming serial data.
'Set timeout to maximum 200 mS
SerialIn (rawstring,Com1,20,0,20)
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CS526 ISFET pH Probe
'Split out digital count value for pH from string input
SplitStr (pHDigit(),rawstring,"String",2,0)
pHCount = pHDigit(2)
NextScan
EndProg
5. Overview
The submersible CS526 is designed to reliably provide accurate pH
measurements over the specified operating temperature range. 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 one of the most significant breakthroughs
in pH testing in half a century and is considered one of the most robust pH
testing technologies available today.
The CS526 is suitable for demanding applications in laboratory and field. The
ISFET performs well in solutions with high solids, moderately aggressive
chemicals, and biological materials. Clogging and junction-contaminating
conditions are well tolerated. See Section 11, Maintenance, for cleaning
procedures.
CS526 electronics are embedded in durable PEEK material, which makes up
the sensor body. The absence of a glass electrode eliminates the potential
hazard of broken glass. The ISFET design considerably reduces the number of
acidic or alkaline errors in extreme pH conditions.
6. Specifications
Features:
•Safety —the ISFET with durable PEEK material can be used safely
in applications where broken glass is a hazard to the user.
•Intelligent electronics —the CS526 combines the latest
developments in ISFET pH sensing technology with state-of-the-art
signal processing. This allows for accurate, fast and reliable results.
•Quality —designed and manufactured under stringent quality control
conditions in an ISO 9001 environment. Each sensor is individually
tested to the most demanding testing protocols, and the electronics
comply fully with directives and with EMC standard
IEC61326:2005.
Compatibility: CR800-series, CR1000, CR3000 dataloggers
Measurement
Range: 1 to 14 pH
Accuracy: ±0.2 pH with 2-point calibration
24 hr drift: <0.15 pH (after 15-min soak in pH 7 at 25°C)
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CS526 ISFET pH Probe
Operating
Temperature: 10° to 40°C
Water Pressure: 0 to 700 kPa (0 to 101.5 psi)
Power Requirement
Source: 5 Vdc
Load: 15 mA maximum
Output: TTL logic, 2400 bps
8 data bits, no parity, 1 stop bit
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: 318 g (11.2 oz)
Dimensions
Length: 102 mm (4 in)
Diameter: 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. Unlike many glass-bulb type pH sensors, the
CS526 ISFET pH probe can be installed without regard to orientation.
7.2 Wiring
TABLE 7-1. CR800, CR850, CR1000, and CR3000 Wiring
Wire Color Wire Label/Function Datalogger Connections
Red (see following
caution)
Power 5V 5V
Black Ground G
White Signal #1 (Rx) Control Port (Tx)
Green Signal #2 (Tx) Control Port (Rx)
Clear Shield G
4