The invention concerns a circuit for controlling the application of the measured value to the input of a measured value receiver which receives the output signal from a sensor element on a substrate, this substrate being provided with the actual sensor element used for determining the respective proportions of particular gases in a gas mixture and with an electrical heating element. The electrical power for the electrical heating element is pulse-width modulated or pulse-timed. The proposed circuit is characterized by the fact that a switch is provided between the output of the sensor element and the input of the measured value receiver and is connected through only when no electrical power is being applied to the electrical heating element.
