Abstract: In order to improve the comparability of the comparison results of monitoring instruments, it is necessary to select a place where the field strength is stable and is not affected by the external electromagnetic environment for comparison. This article analyzes and summarizes the experience and practices of conducting frequency-selective radio frequency electromagnetic radiation monitoring instrument comparison-measurement in a standard anechoic chamber, and finds out some problems that are difficult to detect in daily work.This paper also proposes suggestions for monitoring instrument verification during the monitoring period.Conducting comparisons in a stable and standard electromagnetic field environment could provide a new practice for electromagnetic environment monitoring instrument comparison.

Key words: frequency-selecting, 5G NR signal, electromagnetic radiation monitoring instrument, anechoic chamber, comparative measurement