A detector signal is corrected by superimposing the detector signal with a correction signal. For providing a valid correction signal, a sampling pulse is periodically or randomly provided. The sampling pulse serves as the initiator for sampling a process signal. During the sampling, the process signal is observed. In case a pulse at the process signal is detected, the sampling is assumed as not being suitable to correct the detector signal, since the pulse affects the process signal. Otherwise, the process signal is further observed during a validation period to validate whether the sampled process value of the process signal has already been influenced by an upcoming pulse at the process signal. In case the sampling is assumed as valid, the sampled process value is used as a basis for providing the correction signal.