RF signal power meter RSSI signal strength meter field strength meter EMI RFI RF field electromagnetic field meter EM meter 100 kHz to 3 GHz 0.1 MHz to 3000 MHz 100k-3G 3Ghz covers LF/MF/HF/VHF/UHF bands - UHF technically ends at 3000 MHz 300 MHz to 3000 MHz 300MHz to 3 GHz, although I imagine it will indicate strength of higher frequency signals.
Testing with low power (around 1 watt RF output) UHF handheld radio walkie talkie Luiton LT-458.