An offset determination apparatus and a method are for correcting an offset by supplying a switch-off signal outside a predefinable measuring range of time-expanded sampling values of a reflection signal, which switch-off signal can deactivate a transmitter device at least intermittently in order to generate a predefinable quiescent range within the time-expanded sampling values of the reflection signal and in that, by evaluating at least one sampling value of the time-expanded sampling values which is determined within the quiescent range, a value of an amplitude offset of the time-expanded sampling values of the reflection signal from a normal value is determined and is supplied at an output of the offset provision device.