OS-4, which is designed according to Chinese electromagnetic radiation standards such as GB8702-2014 and HJ/T10.2, is suitable for frequency selective measurement in various complex electromagnetic environments. It can distinguish the frequencies of each radiation source. The antenna covers the frequencies of 100 kHz~6 GHz from low frequency to microwave radiation. It is portable, convenient for field use and distinguishes each radiation source. Signals from mobile operators and wireless service providers are used to determine the proportion of emitter intensity, and the electromagnetic radiation status is evaluated according to the limit curve of GB8702-2014.