Ac Measurement - Greenlee CM-1050 Instruction Manual

AC Measurement

AC measurements are usually displayed as RMS (root mean squared) values. Two methods of
AC measurement are average-responding RMS calibrated and true RMS-reading .
The average-responding RMS calibrated method takes the average value of the input signal,
multiplies it by 1.11, and displays the result. This method is accurate if the input signal is a
pure sine wave.
The true RMS-reading method uses internal circuitry to read the true RMS value. This method
is accurate, within the specified crest factor limitations, whether the input signal is a pure sine
wave, a square wave, sawtooth wave, half wave or signal with harmonics. The ability to read
true RMS provides much more measurement versatility. The Greenlee CM-1050 is a true RMS
meter.
Waveforms and Crest Factors
W v a f e r o m
R M S V l a e u 1 0 0
A e v a r e g V l a e u 0 9
C e r t s F c a o t * r
1 4 . 4 1
( )
* The crest factor is the ratio of the peak value to the RMS value; it is represented by the
Greek letter .
8
1 0 0 1 0 0
1 0 0 7 8
1 . 1 3 7
1 0 0
4 6
2