Method and device for the simultaneous determination of the change in temperature and resistance of sensor resistances of a bridge circuit designed as a quarter or half bridge

摘要

In a method and a device for the simultaneous determination of the change in temperature and resistance of one or more sensor resistances of a bridge circuit designed as a quarter or half bridge, at least two of the comparison resistances with different temperature coefficients α, γ are selected. Different voltages are measured in the bridge circuit, of which at least one voltage drops across one of the resistors of the bridge circuit and which are selected such that the voltage across the bridge circuit, a voltage across the or one of the sensor resistors, and from one or more of the different voltages a voltage can be determined across a parallel comparison resistor. From the measured voltages, known resistance values of the resistors and known temperature coefficients α, β, γ of the resistors of the bridge circuit, the temperature change ΔT and therefrom the change in resistance dR is calculated or vice versa. The process does not require an additional temperature sensor and enables, among other things. a more precise determination of the measured variable.