The Chinese part of the EMC test series covering differential mode disturbances between two and one hundred and fifty kilohertz is associated in China with the load control and communication systems operated by the network companies, and with the smart metering programme that has been deployed on a national scale. The test has two directions of interest for a manufacturer: it establishes that equipment will not be upset by the voltages that other devices inject into the mains, and it establishes that a device intended to receive a mains signalling service will continue to work in the presence of the disturbances found on the network. In Chinese procurement the requirement is imposed through the technical specifications for metering equipment, for distribution automation and for household appliances with communication functions, and the report must identify the disturbance amplitude and modulation used. The page identifies the Chinese designation that a domestic specification will cite.