Cleaning Indicator Electrode And Liquid Junction - YOKOGAWA OR8EFG User Manual

3.1.4

Cleaning Indicator Electrode and Liquid Junction

Staining of a indicator electrode or liquid junction can cause measurement errors. Therefore, if he
measured solutions tend to stain the electrode, the indicator electrode and liquid junction must
be cleaned periodically - depending on the degree of staining. if the ORP Sensor is installed in a
holder with a cleaner, the sensor is continuously (for an ultrasonic cleaner) or intermittently (for a
jet or brush cleaner) cleaned automatically.
Because of this, sensor cleaning is not usually required. However, if the sensor characteristics
are affected by chemical staining, for example, when the sensor is used for ORP measurement
of a highly alkaline solution, carry out acid washing.
To clean the indicator electrode or liquid junction, proceed as follows:
● Stains due to suspended Solids, Sticky Materials, Microbes or the like
Using soft tissue paper, wipe the stains off the indicator electrode or liquid junction. In
addition, clean off remaining stains by rinsing with water.
● Stains due to Oily Materials
Wash off stains by submerging in a neutral detergent solution in a beaker, etc, (for from
several tens of minutes to several hours depending on the degree of staining).
● Chemical Stains such as due to Metallic Adsorption
Place the indicator electrode or liquid junction in a diluted hydrochloric acid solution (1 to
2%) for several minutes (acid washing).
< 3. Maintenance on operation >
IM 12C07J01-01E
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8th Edition : Apr. 27, 2020-00