Patent ID: 7196524

Claim:
An apparatus, comprising; a potentiometric sensor; and a sensor plug head for connection to said potentiometric sensor, wherein: said potentiometric sensor comprises: a working electrode and a reference electrode, for providing a potential difference between said working electrode and said reference electrode, wherein the reference electrode is arranged in a reference electrolyte provided in a liquid container; a connection piece for receiving said sensor plug head, said connection piece being mounted to said working electrode and said reference electrode; and at least one output for issuing a potential-dependent signal, said signal depending on said potential difference, said output being provided at said connection piece; and said sensor plug head comprises: at least one input for receiving said potential-dependent signal from said output; wherein said output and said input each comprise an inductive interface, said potential-dependent-signal being issued by modulation of an AC-signal; and a supply connection element for connecting to the liquid container in order to provide said liquid container with said reference electrolyte.