A POTENTIOMETRIC SENSOR ASSEMBLY AND A METHOD FOR MONITORING THE SENSOR FUNCTION OF A POTENTIOMETRIC SENSOR

摘要

A potentiometric sensor assembly (1) und usage of said sensor assembly comprising- an ion-sensitive electrode (2) including an ion-sensitive glass bulb (3),- a reference electrode assembly (4) including a reference electrode (5),- an ion-sensing circuit (6) having a first terminal (7) connected to the ion-sensitive electrode (2) and a second terminal (8) connected to the reference electrode (5), said circuit (6) being designed to measure the potential difference (V1) that develops in the loop between the reference and the ion-sensitive electrode (5, 2),- a digital storage unit (9) which is designed to save at least an expected range of the additional potential difference (ΔV1) characterizing healthy function of the sensor and/or a range of values of the electric impedance (Rglass) of the glass bulb (3) characterizing a healthy function of the sensor, wherein the ion-sensing circuit is further designed toa) inject a pre-defined electric test current (I1) from the ion-sensing circuit (6) into the loop comprising the reference and the ion-sensitive electrode (5, 2),b) monitor the additional potential difference (ΔV1) that develops in the loop between the reference and the ion-sensitive electrode (5, 2) in reaction to the injection of the test current (I1),c) determine if the additional potential difference (ΔV1) is within an expected range characterizing healthy function of the sensor.