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In general, electrode maintenance should only be necessary about once per year for steady-state polarographic sensors and about once every 3 months for steady-state galvanic sensors. Do not perform the following maintenance procedures just because a sensor ‘looks’ dirty. Only perform the following procedures if the instrument will not calibrate or if the readings are unstable and a regular membrane change did not correct either of these problems. httphttps://www.eidusafondriest.com/pdf/Theoryysi_do_DOhandbook.htm#Cleaning of sensorspdf
The following points should be emphasized when carrying out the cleaning and maintenance process. Source: http://www.eidusa.com/Theory_DO.htm#Cleaning of sensors
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