What type of instrument can be used to accurately measure an RF field strength?
A receiver with digital signal processing (DSP) noise reduction
A calibrated field strength meter with a calibrated antenna✓Bonne réponse
An SWR meter with a peak-reading function
An oscilloscope with a high-stability crystal marker generator
Explication
Measuring an RF field in absolute terms requires an instrument whose response has been calibrated against a known standard, together with an antenna of known gain and pattern, because the reading has to convert to volts per meter or milliwatts per square centimeter. SWR meters and receivers are relative-reading instruments and cannot produce a traceable field strength figure.