Amprobe ACD-16-PRO Clamp-Meters - Manual (Page 5)

4
4 ) OPERATION
ACV & DCV functions
Set the slide-switch function-selector to the position. Default at last selected function.
Press SELECT button to toggle between ACV and DCV measurement functions. There is no
LCD annunciator for DC. LCD annunciator “ ” turns on to indicate AC is selected.
Line-level Frequency function
When voltage or current function is selected, press Hz button momentarily toggles to
Line-level Frequency function. Frequency trigger levels vary automatically with function
ranges.
T
HD%-R Total Harmonic Distortion - RMS function (ACD-40PQ only)
THD%-R = (Total Harmonics RMS / Total RMS) x 100%
Total Harmonic Distortion - RMS (THD%-R) is the percentage ratio of the Total Harmonics
RMS value to the Total (Overall) RMS value of a voltage or current signal, and is given by
the above expression. An ideal sinusoidal waveform has a value of 0 %. A badly distorted
sinusoidal waveform may have a much higher THD%-R value of approaching one hundred
(100% is the maximum theoretical reading).