OxyTechw² GAL Instruction Manual
10 Maintenance
10.1 General cleaning
OxyTechw² Sensors must always be kept clean, particularly in the vicinity of the membrane. Any bio-film
could lead to measurement errors.
Regular inspection and cleaning is required to ensure the sensors works to the optimum performance.
Cleaning frequency will depend on the sample being measured. With a new installation, a weekly inspection
is advised for the first few weeks. The condition of the sensor after these inspections will determine the
frequency of cleaning thereafter.
If the membrane is dirty, clean the sensor head with warm water and soapy water. Use a sponge, but never
use abrasive sponges with a scouring pad. Rinse before returning to the sample.
10.2 Inspection
If the sensor measures an offset in measurements during use, clean the sensor and calibrate as above.
If calibration cannot be performed (Invalid measurements or errors), the membrane and electrolyte may need
to be replaced.
10.3 OxyTechw² GAL Refurbishment
Using Replacement Kit
PN225690
Ensure you have the correct membrane to carry out the replacement. The Membrane is a D10MC
membrane and comes with grey backing paper.
These sensors are type 3 sensors and denoted by the 3 dots on the top part near the cable gland, and
have a type 3 anode and electrolyte. The electrolyte is blue in colour, but becomes very dark over
time with deposits from the sensor.
1. Remove the sensor, and ensure it is thoroughly cleaned before attempting the unscrew the body.
Unscrew the cap. If the cap is difficult to unscrew, give the body a gentle tap with a hammer to help
release the cap (ensure you do not damage the body). Discard the electrolyte inside, rinse the cap
and top parts of the sensor to remove any brown or black oxide deposits.
2. Inspect the anode. If the electrolyte was correctly
filled during the last membrane replacement, the
dark deposits should clean away easily with a
small brush or similar. If the sensor was not
correctly filled, the anode may be badly corroded
and require replacement Before attaching the
anode (PN224697) remove any corrosion marks
with 'Scotchbrite' or fine emery cloth. Discard
anode if badly pitted. Wash in warm soapy water,
then rinse well with deionised water before drying
with paper towel. The anode is fixed onto the
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