Method and device for monitoring an automatic drift compensation

A method for monitoring an automatic drift compensation of a scintillation counter having a scintillator, comprising:

• applying the radiation from a working radiation source with a working radiation source energy spectrum to the scintillator for automatic drift compensation,
• applying the radiation from a monitoring radiation source with a monitoring radiation source energy spectrum, which differs from the working radiation source energy spectrum, to the scintillator, and
• evaluating a counting rate caused by the monitoring radiation source for the purpose of monitoring the automatic drift compensation
• wherein the automatic drift compensation comprises:
• generating amplified electrical pulses having a level that is dependent on the energy of an observed particle of the radiation source and on a gain of the amplification,
• determining a first counting rate of pulses having a level that lies above a first threshold,
• determining a second counting rate of pulses having a level that lies above a second threshold, the second threshold lying above the first threshold, and
• controlling the gain in such a way that a ratio between the first counting rate and the second counting rate corresponds to a predetermined function, in particular remains constant.