Shielded Rooms

Electromagnetic field and line-conducted interference needs to be eliminated in order to measure low-intensity partial discharges with a PD background noise level (≤ 1 pC) in accordance with IEC 60270.

The effect of electromagnetic field interference caused by radio signals, radar stations, welding arcs, etc. can be limited by a shielded room, also known as a Faraday cage.

Line-conducted interference caused by switching signals from thyristor switches and power switches, for example, can be dampened by means of high-frequency filters.

The design and size of the shielded rooms will be determined depending on the specific application. They are separated into a test and control room. Furthermore they are equipped with a PD-free lighting system, emergency lighting, and security loop. There is the option of equipping the room with air-conditioning and a crane, as well.

The high-frequency filters are used to filter the power and control input and the communications lines. The high-frequency filters are installed as close to the shielded rooms as possible to ensure optimal attenuation.