The four types of light duty pH probe - flow-through, thread mount, submersion and immersion, all have sealed combination electrodes. They are built up in the same manner, and should be maintained in the same manner.
Regular maintenance is limited to keeping the electrode clean - as with all pH probes. Soapy water works wonders, but in stubborn cases you can use a dilute bleach (sodium hypochlorite) solution. Unstable readings are usually caused by a dirty electrode.
Sealed combination electrodes have a long, but finite lifetime, and need replacing when they no longer can be calibrated up to the correct values. When replacing electrodes start by cleaning and drying the whole probe. Make sure that no moisture will be able to reach the top of the new electrode or the connector in the upper part that mates with it - i.e. do not change electrodes outdoors in rainy weather or in other wet environments.
When you dismantle the probe, as shown in the illustration overleaf, carefully note the exact position of any O-rings and gaskets sealing the electrode top, and reassemble in a similar manner. Remember to calibrate the new electrode.
- Stable measurements - insensitive to electrical disturbance.
- Wide range of probe types - special fittings and designs available on request.
- Manufactured from PVC. Special materials available on request.
- Hermetically sealed top with preamplifier eliminates moisture problems.
- Easy and quick electrode replacement when needed.
SpecificationspH Range: 0-14 pH.
Operating Conditions: Max. 0.6 bar. Max. temperature 60°C.
Size: Max. diameter 50 mm. Height approx. 240 mm (to top of cable gland).
Thread Mount Type: 1" BSP thread. Other threads on request.
Flow Through Type: Fitted with pipe T-piece, from 3/4" (NW 20) to 2" (NW 50). This type is made to order. The electrode tip extends into the pipe.
Electrode lifetime: Strongly dependent on operating temperature, pressure and the nature of the process fluid.
Ordering InformationLight-Duty pH Probes, shipped complete with electrode and 2 x 250 ml calibration buffer solution:
K02PF: Flow-through probe, 3/4" to 2", please state when ordering.
K02PM: Immersion probe, 500 mm. Other lengths on request.
K02PS: Submersion probe.
K02PT: Thread-mount probe, 1" BSP. Other thread sizes on request.
The flow-through, submersion and thread-mount probes can be ordered with a 1" pipe thread at the top.
Please add suffix "TT" to the ordering number.
Spares:K10PELLD: Light-duty pH electrode.
K10E4500: 500 ml pH 4 calibration buffer.
K10E41L: 1 l pH 4 calibration buffer.
K10E7500: 500 ml pH 7 calibration buffer.
K10E71L: 1 l pH 7 calibration buffer.
OxyGuard pH probes are not sensitive to moisture when they are assembled, but electrode exchange MUST take place in dry conditions - the electrode top and connector inside the preamplifier must be completely dry when put together.