The R&S®MDS-21 absorbing clamp meets the requirements of CISPR 16-1-3/EN 55016-1-3 for disturbance power measurements in the frequency range of 30 MHz to 1000 MHz and is applicable for screening effectiveness measurements.
The disturbance emitted by electrical appliances, machines and systems must comply with the limits specified in national and international standards. MDS absorbing clamps (Meyer de Stadelhofen) in conjunction with EMI measuring receivers are used to measure the disturbance power on cables in line with CISPR 13/EN 55013, CISPR 14-1/EN 55014-1 and EN 50083-2. They can also be used in conjunction with two-port measuring devices to measure the screening effectiveness of cables in line with IEC 62153-4 and EN 50083-2.
MDS absorbing clamps are also used to test the efficiency of disturbance suppression devices for high-voltage ignition systems in line with CISPR 12/EN 55012.
In the frequency range below 30 MHz, the interference stipulated in many standards is defined by measuring the disturbance voltage produced by the EUT at the terminals of a line-impedance stabilization network. This is important because disturbance in this frequency range is mainly propagated via cables.
Above 30 MHz, where radiated disturbance is predominant, the interference is defined by the disturbance field strength at a certain distance. Small EUTs mainly emit disturbance via connected cables, e.g. power cables. For this reason, and also to reduce extensive field strength measurements to a minimum, many standards stipulate the MDS absorbing clamp to measure the disturbance power.
