18
IM CL255
*Effective Value (rms)
Most alternating currents and voltages are expressed in effective values,
which are also referred to as RMS (Root-Mean-Square) values. The
effective value is the square root of the average of square of alternating
current or voltage values.
Many clamp meters using a conventional rectifying circuit have "RMS"
scales for AC measurement. The scales are, however, actually calibrated
in terms of the effective value of a sine wave though the clamp meter is
re-sponding to the average value. The calibration is done with a conversion
factor of 1.111 for sine wave, which is found by dividing the effective value
by the average value. These instruments are therefore in error if the input
voltage or current has some other shape than sine wave.
*CF(Crest Factor) is found by dividing the peak value by the effective value.
Examples:
DC: CF=1
Sine wave: CF=1.414
Square wave with a 1:10 duty ratio: CF=3
■ General Specifications
●Operating System : ΔΣmodulation
● Measurement Function : AC current, DC current, AC voltage, DC voltage,
resistance, continuity check, frequency
●Display : Liquid crystal display with maximum counts of 3999
