Patent ID: 8330470

Claim:
Device for checking the operability of a sensor element for determining the concentration of gas components in a gas mixture, particularly the concentration of gas components in the exhaust gas of internal combustion engines, having a first external pump electrode and an internal pump and Nernst electrode, a measuring resistor and a balancing resistor connected parallel thereto being provided between the external electrode and a probe pin, and a pump current being impressible into the external pump electrode by means of a pump current source, and a measuring voltage incident between the external electrode and the probe pin being detectable via a measuring and analysis device wherein an activatable switch means is disposed in series to the measuring resistor, which can be switched at a high impedance for a predetermined amount of time, during which the voltage across the measuring resistor is detected and analyzed in the measuring and analysis device, and that an error output occurs upon a predetermined voltage threshold value being exceeded.