Fieldpiece SC77 True RMS Clamp Meter with Temperature, Capacitance and Backlight Works with Fieldpiece Accessory Heads -- Take ambient air or refrigeration line temperatures and more with the built-in K-type port and the included ATB1 wrap tab thermocouple. Non-contact Voltage: With the NCV tab on the tip of the clamp close to an AC voltage, press and hold the NCV button. The NCV LED will light with an analog feel and the beeper will beep. The closer you get to AC voltage, the louder the beep. The NCV function is sensitive enough to detect 24VAC on thermostats (24V to 600V, 50Hz to 60Hz). High Voltage and Continuity Indicators: The Hi-V LED and beeper let you know when youve hooked up to a circuit over 30V. The continuity LED and beeper tells you if a circuit is open or closed. 300AAC:Amp Clamp reads 0-300 amps with 0.1 resolution -- Capacitance (MFD) -- Microamps DC: Flame Rectification Tests True RMS: The actual true RMS value is sensed for a wave form within the limits of the crest factor. Either sensing method will give the same results on a clean sine wave but they may differ on a non-sinusoidal waveform.