A method of detecting sensor element resistors

Method for measuring the resistance of the element is used for determining the oxygen concentration in a gas sample of an oxygen sensor, wherein a time constant is set corresponding to a frequency at which the curve of the impedance (ZAC) of the oxygen sensor (30) is uniform, is applied to the oxygen sensor, a voltage (Vp), which varies with the time constant, a current change caused by the voltage change (.DELTA.I) of the current flowing in the oxygen sensor current (Ip) is determined and the element resistance (R) of the oxygen sensor from the voltage change (.DELTA.V) and the current change (.DELTA.I) is determined, wherein wherein adjusting the time constant, a frequency range is determined, in which the curve of the impedance (ZAC) of the oxygen sensor (30) is uniform, the time constant is set according to a specific frequency within the frequency range, a voltage is applied as a changed voltage (Vp), which changes with a negative slope portion and a portion of positive slope, as a change in current (.DELTA.I) the ...