The immersion probe has two functions:
Firstly, the immersion probe prevents the agitator from starting if the probe is not covered with substrate. The isolating amplifier, which is often provided by the customer, measures the resistance, which is higher in the air than in the substrate: the agitator can only be started when the probe is immersed. In this way, the immersion probe also serves to prevent sparking in the potentially explosive gas area.
On the other hand, the immersion probe conducts the leakage current through the agitator in the direction of the earth, thus preventing major electrocorrosion damage.
The probe can be attached to the guide unit (immersion probe) or to the terminal box (KKS - cathodic corrosion protection) if the installation space is tight (e.g. slewing ring of the MGD or similar). The probes can also be retrofitted.