G 1610
Measurement Basics | 5
B-H86.0.2X.DK2-3.0
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5
Measurement Basics
5.1
The oxygen sensor
5.1.1
Explanation
The oxygen sensor is an active sensor. It consists of a platinum cathode, a lead anode
and potassium hydroxide (KOH) as an electrolyte. If oxygen is present, it is reduced on
the platinum cathode and the sensor delivers a signal. If no oxygen is present, no
signal is delivered. The anode is consumed by the oxygen measurement. The sensor
ages. Furthermore, the sensor loses water through the permeable membrane, in
particular, when it is stored in dry air. Therefore, it should be checked and maintained
regularly and replaced as necessary.
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DANGER
Potassium hydroxide!
The oxygen sensors contain potassium hydroxide. H290 can corrode metal. H314
causes severe caustic burns. All contact with the skin, clothing and eyes should be
avoided. Nevertheless, should contact occur, take the following measures.
– As a fundamental rule, protective equipment (e.g. gloves) must be worn as in-
tended for the purpose of use!
– Do not eat, drink or smoke in areas where chemicals are used!
– In case of problems, consult with trained, qualified personnel immediately!
– Eyes: Flush with flowing water for at least 15 minutes, seek medical attention!
– Skin: Wash with large amounts of water for several minutes!
– Clothing: Remove immediately!
– If swallowed: Drink large amounts of water, do not induce vomiting and seek
medical attention!
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NOTE
Always store the oxygen sensor damp. It should always be stored in a storage bottle
filled with water or in a container filled with water. After storage for an extended period,
any potential deposit layers, such as algae, must be cleaned off of the membrane with
a soft paper towel prior to measurement.
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NOTE
Protective glasses must be worn when commissioning, filling and servicing the sensor.