XY condensers are conrected to the mains terminals of electric and electronic machines for protection from radio interferences. It is sure that if measure the radio interference mains voltage of the ma chines using CISPR's artificial mains network, it will be get good result. But under their actual working condition connected to mains lines, they will be sometime suffered from radio disturbance. If connect the resistance to XY condenser in series, they will protect the machines from all kind of radio interferences.
