Valor Fires 820 Manuel d'instructions télécharger pdf (Page 9)

DM-800 • DM-810 • DM-820

*The crest factor is the ratio of the peak value to the RMS value; it is represented by the

Greek letter ξ.

mrofevaW

eulaVSMR 001001001001

eulaVdeifitceR 090017846

*rotcaFtserC

(ξ)

414.1137.12

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 Greenlee DM-800 is an average-responding meter.

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 DM-810 and DM-820 are

true RMS meters.

The Waveforms and Crest Factors table shows some typical AC signals and their RMS values.

Waveforms and Crest Factors

1 2 3 4 5 6 7 8 9 10 11 12 13 14 ... 67 68

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Valor Fires 820 Manuel d'instructions Page 9