Endress+Hauser Oxymax COS22 Series - Clean Sensor; Wear Parts and Consumables

Oxymax COS22 Maintenance
Endress+Hauser 23
10.3 Clean sensor
The measurement can be corrupted by sensor fouling or malfunction, e.g.:
• Buildup on the sensor membrane
•
 causes longer response times and a reduced slope under certain circumstances.
For reliable measurement, the sensor must be cleaned at regular intervals. The frequency
and intensity of the cleaning operation depend on the measuring medium.
Clean the sensor:
• before every calibration
• at regular intervals during operation as necessary
• before returning it for repairs.
Type of soiling Cleaning
Salt deposits Immerse the sensor in drinking water or in 1-5% hydrochloric acid
(for a few minutes). Afterwards, rinse it with copious amounts of
water.
Dirt particles on the sensor shaft and
shaft sleeve (not membrane!)
Clean the sensor shaft and sleeve with water and a suitable brush.
Dirt particles on the membrane or
membrane body
Clean the membrane with water and a soft sponge.
After cleaning, rinse the sensor with copious amounts of clean water.
10.4 Wear parts and consumables
Parts of the sensor are subject to wear during operation. By taking suitable measures, you
can restore the normal operating function.
Measure Reason
Sealing ring replacement Visible damage to a sealing ring
Electrolyte replacement Unstable or implausible measuring signal or fouling of the electrolyte
Membrane body replacement Membrane is damaged or can no longer be cleaned (hole or overstretching)
1 2
3
4
5
78
9
6
A0011868
 9 COS22
1
2
3
Plug-in head
Thrust collar
Sensor shaft
4
5
6
O-ring 8.5 x 1.5 mm
Membrane body
Shaft sleeve
7
8
9
Glass portion with anode and cathode
Process seal 10.77 x 2.62 mm
Process connection Pg 13.5