The Absorbing Clamp MDS 21 C was designed to measure the disturbance power according to CISPR 16-2-2 in the frequency range 30-1000 MHz, it complies to the technical requirements of CISPR 16-1-3. The measurement of disturbance power was introduced in 1969 to the CISPR standardisation. Many fundamental investigations about the clamp construction and the disturbance measurement method itself have been done by the swiss PTT under the leadership of J. Meyer de Stadelhofen, whose initials are still visible in the name of the clamp. Frequency range: 30 MHz – 1000 MHz.