They are very robust and easy to use. They do not need an external supply - they make their own electricity. They can be connected using ordinary cable, that can have any length. Cleaning the membrane is, apart from an occasional calibration, the only routine maintenance necessary. After some years' use a probe will need renovation - but this can be carried out by anyone in just a few minutes at negligible cost.
Renovation entails fitting a new membrane, anode and electrolyte.
True zero - no zero adjustment. Self-exciting galvanic cell. Excellent long-term stability, long calibration and cleaning intervals. No need for regular service, probe renovation intervals up to 2 years or more. Strong membrane, practically unbreakable - special versions available.