How to quickly screen for electrical force measurement switches (PMS) during EMC pre-testing?

Pre-compliance testing during product development can identify potential problems early, saving time and costs associated with later rectification. Rapid screening requires simple yet effective tools and methods.

Conducted emissions pre-testing: Using a Line Impedance Stabilized Network (LISN) and a spectrum analyzer or receiver with quasi-peak detection, measure conducted emissions at the power port in a laboratory power environment and compare to the limit lines.

Radiated emissions pre-testing: In a room with moderate shielding or using a GTEM chamber, scan the 30MHz-1GHz frequency band with a broadband antenna and spectrum analyzer.

Although less accurate than a fully anechoic chamber, it can identify obvious exceedances. Immunity pre-testing: Use a portable EFT/surge simulator, ESD gun, and RF signal generator with an amplifier and antenna to perform simplified immunity tests and observe for any abnormal equipment functions. Near-field scanning kits (probe + spectrum analyzer) are particularly useful for locating noise sources. The key to pre-testing is establishing internal judgment criteria (e.g., 3dB stricter than the official limits) and recording all test data and phenomena to provide a basis for design optimization.