Failure analysis of a measuring sensor with an integrated temperature sensor

A method of characterization and failure analysis of a measuring sensor, the method comprising:

• applying an alternating current having a frequency at a selected voltage to a measuring sensor, wherein the voltage is applied between a working electrode of the measuring sensor and a temperature sensor integrated into the measuring sensor and/or between a reference electrode of the measuring sensor and the temperature sensor, wherein the measuring sensor includes an ion-sensitive membrane and electrical insulation between the temperature sensor, the working electrode and the reference electrode;
• varying the frequency of the alternating current between a lower frequency and an upper frequency over a range having a low frequency end and an upper frequency end, wherein the varying defines a scan;
• measuring an impedance of the measuring sensor between the working electrode and the temperature sensor, and/or between the reference electrode and the temperature sensor, from a single scan over the range of frequencies of the alternating current;
• analyzing the measured impedance to determine a total impedance between the working electrode and the temperature sensor, and/or between the reference electrode and the temperature sensor, and the real and imaginary components of the total impedance at and over the applied frequencies of the alternating current;
• and
• determining whether, based on the total impedance and on the real and imaginary components of the total impedance, the measuring sensor has a defect in the insulation between the working electrode and the temperature sensor or between the reference electrode and the temperature sensor.