EMI absorbing clamp
Com-Power

The absorbing clamps also known as ferrite clamps are used for measuring radio noise power in lieu of radiated emissions measurements. These absorbing clamps meets CISPR publication 14 (EN 55014) for the measurement of interference from household appliances, electrical tools and similar apparatus. It measures radio noise power generated and fed through the power cables of these products above 30 MHz.

The absorbing clamp consists of a calibrated ferrite current transformer operating in the frequency range of 30-1000 MHz and two groups of ferrite rings. The ferrite rings acts as an absorbers of energy and stabilizes impedance. One set of ferrite rings surrounds the lead from the transformer to the EMI meter to minimize standing waves. The second group of ferrite rings surround supply cable from the equipment under test. These rings act as an absorber of energy and an impedance stabilizer to isolate the equipment under test (EUT) from the external power source. These rings are made up of two halves. Therefore, the power cable from the EUT can be placed inside the aperture of the rings.