A measuring device comprises a Terahertz, THz, transmitter configured to emit a THz signal to an object to be measured and a THz receiver configured to receive a reflected portion of said THz signal that has been reflected by said object. The said THz transmitter and said THz receiver are arranged in a measuring head of said measuring device. The measuring device may vary a distance between said measuring head and said object to be measured, emit, by means of said THz transmitter, said THz signal to said object to be measured, receive said reflected portion of said THz signal, and determine a first parameter characterizing a detected signal proportional and/or related to said received reflected portion of said THz signal.