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CS510 OXYGUARD DISSOLVED OXYGEN PROBE
INSTRUCTION MANUAL
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COPYRIGHT (c) 2000 CAMPBELL SCIENTIFIC, INC.
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The CS510-L Oxyguard Dissolved Oxygen Probe is manufactured by Point Four Systems
Incorporated. Point Four’s conditions of sale and return policy apply to these items.
Products may not be returned without prior authorization. To obtain an RMA number
contact Point Four Systems, Inc., phone (604) 936-9936. NOTE: if the product has been
exposed to hazardous media, it must be fully decontaminated and neutralized prior to
return to Point Four Systems.
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CS510 OxyGuard 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 t he measured medi um.
Oxygen diffuses through the membrane onto the cathode, reacts chemically, and
combines with the anode. An electrical current is produced by this chemi cal
reaction which is converted from microamps to millivolts by an in-line resistor.
An in-line thermistor also conditions the s ignal provi ding aut omati c t emperature
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 wit h cathode, anode and cabl e, and a l ower
part comprising a screw on membrane cap with fitted membrane. The cap is filled
with electrolyte and simply screwe d onto t he top component .
The probe is self polarizing and requires no external power s ource. There are
only two wires to connect. Cable length i s rarely a l imi ti ng factor and general ly
there is no need for shielded wire.
Because the probe's output is linear, it is possible to connect it directly to a data
acquisition system capable of handling the small millivolt signal.
The probe's robust construction and simpl e des ign make mai nte nance and
servicing it straightforward. There is no need t o se nd the probe back t o 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 requi red. W hen
necessary probe can be fully overhauled in five minutes.
FIGURE 1-1. CS510-L
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CS510 OxyGuard Dissolved Oxygen Probe
2. Specifications
Principle of Measurement: Membrane covered polarographic oxygen probe—
self polarizing galvanic cell
Output Signal: 5 mV per mg/l, 2 mV per %/ vol nomi nal
Accuracy: Better than +/- 2 % of reading +/- 1 digit when calibration
temperature equals measuring temperature +/- 5 C
Repeatability: Better than +/- 0.2 mg/l; Better than +/- 0.5 %/vol when
barometric pressure unchanged
Output Impedance: 1 kOhm nominal
Response Time:
mg/l: 60 s for 90 % of 100 % step change at constant temperature
%vol: 10 s for 90 % of 100 % step change at constant temperature
Materials of Construction:
Probe body: POM (polyoxymethylene)
O-rings: Viton
Membrane: 0.05 mm (2 mil) Teflon
Dimensions and Weight:
58 mm diameter by 59 mm high (2-1/4 inch diameter by 2-1/4 inch high)
350 g (3/4 lb) including standard 3 m (10 ft) cable length
Cable: 2-conductor, 0.75 square mm (16 gauge), standard length 3 m (10 ft);
other lengths available upon request
Operating Conditions: Temperature: 0 to 50 C (32 to 122 F)
Pressure: Maximum 10 atmospheres (147 psig)
Minimum Submersion Depth: 60 mm (2 ½ in)
Minimum Water Flow: 2.5 cm/s (1 in/sec) across membrane
Calibration: In air or in air saturated water. Use of EasyCal calibrator optional.
Temperature Compensation: Automatic fr om 4 - 40 C (40 - 104 F)
Probe Options:
Type I Type II
Range of dissolved
oxygen
Gaseous oxygen 0-100 %/vol 0-35 %/vol
Electrode materials Ag cathode/Zn anode Ag cathode/Pb anode
Probe electrolyte NaCl Na
0-50 mg/l, 0-500 % Sat 0-15 mg/l, 0-150 % Sat
2CO3
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3. Service Kit
CS510 OxyGuard Dissolved Oxygen Probe
Spare membrane cap with fitted membrane.
50 ml electrolyte.
Spare anode and O-ring.
FIGURE 3-1. Exploded View of CS510-L
4. Optional Probe Accessories
Agitator for stagnant conditions.
Probe Mounting assembly for waste water installations.
Flow-through and by-pass fittings.
EasyCal calibrator for fast and accurate calibration.
5. Optional Agitator
The PT4 Agitator is a reliable and robust agi tat or for us e in conj uncti on wi th
probes subjected to bio-fouling in ponds and stagnant water conditions.
O
probes require a minimum water velocity across thei r membranes t o functi on
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properly. Therefore, to measure DO in stagnant water conditi ons, i t i s neces s ary
to move the water past the membrane to get accurate and reliable DO
measurements. In many instances the water als o has a high bi o-loading and t he
probes become fouled resulting in inaccurate DO measurements.
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CS510 OxyGuard Dissolved Oxygen Probe
The PT4 Agitator overcomes these problems. The device is desi gned s o that a
soft bristle brush sweeps acros s the probe membrane or s ens or ti p. This s weepi ng
action of the brush provides the required water velocit y as w ell as prevents t he
membrane from becoming bio-fouled.
FIGURE 5-1. Preventing Bio-fouling of the CS510-L
The optimum sweeping frequency depends upon the design of probe and type of
membrane used and water conditions. An ON-time of 0.25 s econds and OF F time of 5 seconds is suitable in most circums t ances .
Agitator’s overall size: 7-1/8" x 3-1/4" diameter, 1-1/4 lb. (180mm x 83mm, 0.6 kg)
Supplied with 10 ft. (3 meters) cable.
Power required: 10.5 to 18 VDC at the agitator, 1.1 amps . Maxi mum ON-t ime i s
3 seconds.
FIGURE 5-2. CS510-L with PT4 Agitator
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CS510 OxyGuard Dissolved Oxygen Probe
Optional Repeat Cycle Timer for Agitators
controlled by the optional solid state R e peat C ycl e Timer. It s ends 12 VDC pul s es
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 V DC ; hous ed in w at ert ight cyl inder
6.6" x 2" diameter (170 mm X 50 mm).
6. Application Information
NOTE
Short Cut users: This application note was written primarily for
those whose needs are not met by Short Cut. Your procedure is
much simpler: just add the OxyGuard probe (it’s in the water
quality sensor group), save your program, and follow the wiring
shown in Step 4 of Short Cut.
7. Wiring
The OxyGuard probe uses one differential channel. Differenti al wi ring i s bett er
at rejecting electrical noise and ground loop error.
Red -----------------1H
Blue-----------------1L
: Reciprocating action may be
8. Programming
*1 Table 1
01: 15 Sec. Execution Interval
01: Volt (Diff) (P2)
01: 1 Rep
02: 24 250 mV
03: 1 Diff Chan
04: 1 Loc: [DO ]
05: 1 Mult.
06: 0 Offset
9. Calibration
Instruction 2, differential millivolt measurement is required for the OxyGuard
probe. The example measurement instructions that foll ow do not s t ore data t o
final storage. Additional inst ructi ons (Typical l y P92, P 77 and output proces s ing
instructions such as P70) are required to st ore data permanentl y.
*See calibration*
The multiplier is used to calibrate the OxyGuard probe. To calculate the
multiplier:
1) Program the CR10(X) using a multiplier of one.
2) Place the OxyGuard probe in the air, shaded from the sun. Wait for readings
to stabilize. This may take 15 minutes or more.
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CS510 OxyGuard Dissolved Oxygen Probe
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3) Determine the air temperature and barometric pressure.
4) Using a calibration chart such as t hat provided i n the 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 )
R = The signal output of the OxyGuard probe when using a multiplier of one
6) Change the multiplier in the CR10 program from one to the calculated
number.
10. Maintenance
The OxyGuard 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 wi th your fi ngernail .
Please see the OxyGuard manual for complete maintenance procedures.
11. Agitator Control
In low flow conditions (less than about 2 cm/sec), it may be necessary to add
an agitator to the OxyGuard probe. The distributor for OxyGuard in North
America sells a self-timed agitator which can be purchased through Campbell
Scientific. The self-timed agitator 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/
Datalogger
Port C1
4 1
#7321 Rela y
Crydom D1D07
3 2
BLACK
WHITE
+ -
Agitator
12 V Battery
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CS510 OxyGuard Dissolved Oxygen Probe
The following instructions in program table 2 would trigger the agitator as
discussed in the agitator manual:
*Table 2 Program
02: 2.0 Execution Interval (seconds)
1: Do (P86)
1: 41 Set Port 1 High
2: Excitation with Delay (P22)
1: 1 Ex Channel
2: 0 Delay W/Ex (units = 0.01 sec)
3: 25 Delay After Ex (units = 0.01 sec)
4: 0 mV Excitation
3: Do (P86)
1: 51 Set Port 1 Low
The above example is not as power efficient as possible, and would require AC
power. 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.
; Use port number as wired
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CS510 OxyGuard Dissolved Oxygen Probe
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