Measurement amplification methods and devices for detecting the detuning of a measurement bridge (10) to which a bipolar, rectangular supply voltage (Us) is supplied. The methods and devices use integrating A/D conversion and are characterized in that a reference voltage (Uref) used for the A/D conversion undergoes polarity changes synchronized with the polarity changes of the supply voltage (Us). Offset and drift are eliminated by totaling an even number of individual measurements.