The $r $n electromagnetic radiation measurement terminal of the ST100 power frequency electromagnetic radiation online monitoring system can be used in various fields such as environmental protection, power companies, power science research institutes, emergency centers, universities, research institutes, laboratories, system integrators, etc., with 24-hour * 365 day online monitoring. Some usage scenarios are as follows: $r $n real-time monitoring of electromagnetic environment in green substations and demonstration stations; $r $n popularization and publicity of green substations; Monitoring of electromagnetic environment quality points in $r $n; $r $n Electromagnetic Environment Monitoring and Related Research; $r $n Workplace electromagnetic environment monitoring and monitoring data disclosure.