Method for checking a lightning conductor of a lightning protection system comprised by a rotor blade of a wind turbine, wherein the wind turbine comprises a device for checking the lightning conductor and the rotor blade comprising the lightning conductor , wherein the device for checking the at least one lightning conductor is designed and/or configured to carry out and/or to execute the method, and wherein the device is a time domain reflectometry device and comprises at least one pulse generator for introducing a pulse and a measuring device for determining the pulse response, the method comprising: - determining , by the measuring device , a pulse response information indicative of a pulse response, wherein the pulse response information is determined based on an pulse introduced into the lightning conductor characterized by an electromagnetic wave, wherein the pulse response information represents at least a waveform and a propagation time determined on the basis of the reflection of the pulse after it has been introduced; - determining , by the device , an evaluation information based on the determined pulse response information, wherein the pulse response information is analyzed at least with regard to the represented waveform and the runtime of the introduced and reflected electromagnetic wave, wherein the evaluation information is indicative of whether the lightning conductor is functional or not; and - outputting or causing an output , by the device , of the determined evaluation information; wherein determining the evaluation information comprises a comparison of the waveform and/or propagation time represented by the pulse response information with at least one reference information indicative of a pulse response information of an undamaged lightning conductor, and a further measuring of the lightning conductor to ensure that the lightning conductor is undamaged. - determining , by the measuring device , a pulse response information indicative of a pulse response, wherein the pulse response information is determined based on an pulse introduced into the lightning conductor characterized by an electromagnetic wave, wherein the pulse response information represents at least a waveform and a propagation time determined on the basis of the reflection of the pulse after it has been introduced; - determining , by the device , an evaluation information based on the determined pulse response information, wherein the pulse response information is analyzed at least with regard to the represented waveform and the runtime of the introduced and reflected electromagnetic wave, wherein the evaluation information is indicative of whether the lightning conductor is functional or not; and - outputting or causing an output , by the device , of the determined evaluation information; wherein determining the evaluation information comprises a comparison of the waveform and/or propagation time represented by the pulse response information with at least one reference information indicative of a pulse response information of an undamaged lightning conductor, and a further measuring of the lightning conductor to ensure that the lightning conductor is undamaged. <EOS>