Campbell Scientific CS512 User Manual

Campbell Scientific CS512

Oxyguard Type III

Dissolved Oxygen Probe

Revision: 12/06

Copyright © 2001-2006

Campbell Scientific, Inc.

Warranty and Assistance

The CS512 OXYGUARD TYPE III DISSOLVED OXYGEN PROBE 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

CAMPBELL SCIENTIFIC, INC. does not accept collect calls.

CS512 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 Information.....................................................1

2. Specifications ..............................................................2

3. Optional Probe Accessories.......................................3

4. Optional Agitator .........................................................3

5. Application Information ..............................................4

6. Wiring............................................................................4

7. Programming ...............................................................5

8. Calibration....................................................................6

9. Maintenance.................................................................7

10. Agitator Control.........................................................7

Appendix

A. Dissolved Oxygen in Fresh Water Table ............... A-1

Figures

1-1. CS512......................................................................................................1

4-1. Preventing Bio-fouling of the CS512......................................................3

4-2. CS512 with PT4 Agitator........................................................................4

10-1. Agitator Wiring.....................................................................................7

Table

6-1. Sensor Wiring..........................................................................................4

i

CS512 Table of Contents

Examples

1. Sample Program using P1..........................................................................5

2. Sample Program using P2..........................................................................5

3. Sample Program using VoltSE .................................................................. 5

4. Sample Program using VoltDiff ................................................................ 5

5. Sample Program using VoltSE .................................................................. 5

6. Sample Program using P36........................................................................6

7. Sample Program using Expression ............................................................ 6

8. Sample Program using P86 and P22 Instructions...................................... 8

9. Sample Program using Portset................................................................... 8

10. Sample Program using Portset................................................................. 8

ii

Campbell Scientific CS512 Oxyguard Type III Dissolved Oxygen Probe

An accurate and reliable sensor is a critical element in any measurement system. The
Oxyguard Stationary Probe meets these criteria for the measurement of dissolved oxygen.

1. General Information

The Oxyguard Stationary Probe is a galvanic probe which produces a millivolt
signal proportional to the amount of oxygen present in the m easured m edium .
Oxygen diffuses through the membrane onto the cathode, reacts chemically, and
combines with the anode. An electrical current is produced by this chemical
reaction which is converted from microamps t o mi llivol ts by an in-l ine resistor.
An in-line thermistor also conditions the signal providing aut omat ic tem perature
compensation. With these features, the probe produces a millivolt output
proportional to the oxygen present in the medium in which it is placed. The probe
consists of two parts, an upper part with cathode, anode and cable, and a lower part
comprising a screw on membrane cap with fitted membrane. The cap is filled with
electrolyte and simply screwed onto the top com ponent.

The probe is self-polarizing and requires no external power source. There are two
wires to connect.

Because the probe's output is linear, it is possible to connect it directly to a data
acquisition system capable of handling the smal l m illi volt signal .

The probe's robust construction and simple design make m ai ntenance and
servicing it straightforward. There is no need to send the probe back to the factory
for servicing. It utilizes a strong, easy-to-clean and easy-to-change membrane in a
screw-on membrane cap. Regular servicing is not required. When necessary the
probe can be fully overhauled in five minutes.

FIGURE 1-1. CS512

1

Campbell Scientific CS512 Oxyguard Type III Dissolved Oxygen Probe

2. Specifications

Principle of Measurement: Membrane covered galvanic oxygen probe
Output Signal:

2.5 to 5 mV per mg 1

-1

Repeatability:

Output Impedance:
Response Time: After equilibration, 1 minute for 95% of final

Materials of Construction:
Probe body:
O-rings:

Membrane:
Dimensions and Weight: 2.28” diameter x 2.3” height

Cable: standard length 7 m (23 ft); other lengths

Operating Conditions:
Temperature
Pressure:
Minimum Submersion Depth:
Minimum Water Flow:

Calibration: In air or in air saturated water

Better than ±0.2 mg/l calibration temperature
equals measuring temperature ±5°C

∼1 kohm

value

Delrin
Membrane O-ring = Buna N
Body Seal O-ring = Viton

0.05 mm (2 mil) Teflon

15.9 oz.

available upon request
2-wire 22 awg shielded, PVC jacketed

0° to 40°C (32° to 122°F)
0 to 29 psig
60 mm (2 ½ in)
1 cm/s (.39 in/sec) across membrane

Temperature Compensation:
Range of Dissolved Oxygen: 0-20 mg/l, 0-200% Sat
Ships with: 5 spare membranes with O-rings

Automatic from 4° - 40°C (40° - 104°F)

50 ml electrolyte
cathode cleaning pad

2

Campbell Scientific CS512 Oxyguard Type III Dissolved Oxygen Probe

3. Optional Probe Accessories

PT4-L — Agitator for stagnant conditions
18026 — DO electrolyte, 1 liter
18027 — Membrane kit, 10 membranes

4. Optional Agitator

The PT4 Agitator is a reliable and robust agitator for use in conjunction wit h
probes subjected to bio-fouling in ponds and stagnant water conditions.

probes require a minimum water velocity across their m em branes to function

O

2

properly. Therefore, to measure DO in stagnant water conditions, it is necessary to
move the water past the membrane to get accurate and reliable DO measurements.
In many instances the water also has a high bio-loading and the probes become
fouled resulting in inaccurate DO measurements.

FIGURE 4-1. Preventing Bio-fouling of the CS512

The PT4 Agitator overcomes these problems. The device is designed so that a soft
bristle brush sweeps across the probe membrane or sensor tip. This sweeping
action of the brush provides the required water velocity as well as prevents the
membrane from becoming bio-fouled.

The optimum sweeping frequency depends upon the design of probe and type of
membrane used and water conditions. An ON-tim e of 0.25 seconds and OFF-tim e
of 5 seconds is suitable in most circumstances.

Agitator’s overall size: 7-1/8" x 3-1/4" diameter, 1-1/4 l b. (180mm x 83m m , 0.6 kg)
Supplied with 10 ft. (3 meters) cable.
Power required: 10.5 to 18 VDC at the agitator, 1.1 amps. Maximum ON-time is

3 seconds.

3

Campbell Scientific CS512 Oxyguard Type III Dissolved Oxygen Probe

FIGURE 4-2. CS512 with PT4 Agitator

Optional Repeat Cycle Timer for Agitators
controlled by the optional solid state Repeat Cycl e Tim er. It sends 12 VDC pulses
to the agitator coil. The ON-time is 0.25 sec. The OFF-time is adjustable from 3
to 12 sec.; requires supply voltage 10 to 17 VDC; housed in watertight cy linder

6.6" x 2" diameter (170 mm X 50 mm ).

5. Application Information

NOTE

SCWin users: This manual was written primarily for those
whose needs are not met by SCWin. Your procedure is much
simpler: just add the CS512 probe (it’s in the water folder), save
your program, and follow the wiring shown in Step 2 of SCWIN.

6. Wiring

The CS512 probe can use one differential channel or one single-ended channel.
Differential wiring is better at rejecting electrical noise and ground loop error.

Colo
r

Functio
n

: Reciprocating action may be

TABLE 6-1. Sensor Wiring

CR510, CR10X, CR800, CR850,
CR23X, CR1000, CR3000

CR200 Series

4

White Signal + Differential High,

or Single-Ended Channel

Blue Signal - Differential Low or AG Ground

Single-Ended
Channel

7. Programming

1: Volt (SE) (P1)
1: 1 Reps
2: 24 250 mV 60 Hz Rejection Range ; code 23 used for CR23X
3: 1 SE Channel
4: 1 Loc [ DOmV ]
5: 1.0 Multiplier *See Calibration*
6: 0.0 Offset

1: Volt (Diff) (P2)
1: 1 Reps
2: 24 250 mV 60 Hz Rejection Range ; code 23 used for CR23X
3: 1 DIFF Channel
4: 1 Loc [ DOmV ]
5: 1.0 Multiplier *See Calibration*
6: 0.0 Offset

Campbell Scientific CS512 Oxyguard Type III Dissolved Oxygen Probe

In the CR510, CR10X, and CR23X datalogger, Instruction P1 or P2 can be used.
Example 1 uses a single-ended measurement for the CS512 probe; exam ple 2 uses
a differential measurement. The example measurement instructions that follow do
not store data to final storage. Additional instructions (ty pically P92, P77, and
output processing instructions such as P70) are required to store data permanently .

EXAMPLE 1. Sample Program using P1

EXAMPLE 2. Sample Program using P2

In the CR1000, CR800, CR850, and CR3000 dataloggers, instruction VoltDiff
or VoltSE is used to measure the CS512 probe.

EXAMPLE 3. Sample Program using VoltSE

VoltSE (DOmV,1,mV250,1,1,0,_60Hz,1.0,0)

EXAMPLE 4. Sample Program using VoltDiff

VoltDiff (DOmV,1,mV250,1,True ,0,_60Hz,1.0,0)

In the CR200 series dataloggers, only the instruction VoltSE is used to
measure the CS512 probe.

EXAMPLE 5. Sample Program using VoltSE.

VoltSE (DOmV,1,1,1.0,0)

5

Campbell Scientific CS512 Oxyguard Type III Dissolved Oxygen Probe

8. Calibration

The multiplier is used to calibrate the CS512 probe. To calculate the multiplier:

1) Program the datalogger using a m ultiplier of one.

2) Place the OxyGuard probe in the air, shaded from the sun. Wait for readings

to stabilize. This may take 15 minut es or more.

3) Determine the air tem perature and barometric pressure.

4) Using a calibration chart such as that provided in t he probe’s manual ,

determine the oxygen concentration of the air.

5) Use the following equation to calculate the multiplier:

M = P/R
M = Multiplier
P = Concentration in PPM of the air (from the calibration chart in Appendix A)
R = The signal output of the OxyGuard probe when using a multiplier of one

6) Change the multiplier in the datalogger program from one to the calculated

number.

A more common way to enter the multiplier is to insert a separate instruction in
the program. This will allow a new multiplier to be added to the program
without rewriting, compiling, and downloading the program to the data logger.

In the CR510, CR10X, and CR23X, use Instruction P36. The multiplier is
entered into an input location called DOmult using the numeric display in
PC200W, PC208W, LoggerNet, PC400, PConnect, PConnectCE, or the
CR10KD.

EXAMPLE 6. Sample Program using P36

57: Z=X*Y (P36)
1: 1 X Loc [ DOmV ]
2: 2 Y Loc [ DOmult ]
3: 3 Z Loc [ DOppm ]

In all dataloggers that use CRBasic, an expression is written. The multiplier
value is entered into the expression through the Public Table using the numeric
display in PC200W, LoggerNet, PC400, PConnect, and PConnectCE.

EXAMPLE 7. Sample Program using Expression

DOppm = DOMult * DOmV

6

Campbell Scientific CS512 Oxyguard Type III Dissolved Oxygen Probe

9. Maintenance

The CS512 probe needs little maintenance. Regular cleaning of the membrane is
all that is required. The membrane is very durable and can be cleaned with a cloth
or soft paper. Do not scratch it clean with your fingernail.

10. Agitator Control

In low flow conditions (less than about 5 cm/sec), it may be necessary to add
an agitator to the CS512 probe. Campbell Scientific ships the agitator with a
repeat cycle timer. Using the repeat cycle timer requires no datalogger
programming. However, some users choose to use a solid state relay and have
the datalogger agitate the water on the probe face either periodically
throughout the day or just before measurement. Agitating just before the
measurement saves on power and causes less wear and tear on the agitator and
probe membrane.

The wiring for the agitator as controlled by this example program would be as
follows:

Ground/G

Datalogger

Port C1

4 1

#7321 Relay

Crydom D1D07

3 2

FIGURE 10-1. Agitator Wiring

The following instructions would trigger the agitator as discussed in the
agitator manual.

In the CR510, CR10X, and CR23X, use instruction P86 and P22.

BLACK

WHITE

+ -

12 V Battery

Agitator

7

Campbell Scientific CS512 Oxyguard Type III Dissolved Oxygen Probe

EXAMPLE 8. Sample Program using P86 and P22 Instructions

45: Do (P86)
1: 41 Set Port 1 High

46: Excitation with Delay (P22)
1: 1 Ex Channel
2: 20 Delay W/Ex (units = 0.01 sec)
3: 0 Delay After Ex (units = 0.01 sec)
4: 0 mV Excitation

47: Do (P86)
1: 51 Set Port 1 Low

48: End (P95)

In the CR200 series dataloggers, use the Portset instruction.

EXAMPLE 9. Sample Program using Portset

Portset (1,1)
Delay(500,msec)
Portset(1,0)

In the CR1000, CR800, CR850, and CR3000 dataloggers, use the Portset
instruction.

Portset (1,1)
Delay (1,500,msec)
Portset (1,0)

EXAMPLE 10. Sample Program using Portset

The above example is not as power efficient as possible and would require AC
power to maintain a sufficient battery charge. If it is necessary to operate an
agitator without AC power available, write the program so that the agitator is
only operated for a short period of time just before the measurement is to be
taken.

8

Appendix A. Dissolved Oxygen in Fresh Water Table

A-1

Appendix A. Dissolved Oxygen in Fresh Water Table

A-2

This is a blank page.

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