Model UT231: OPERATING MANUAL

24

True RMS Measurement and Average Value
Measurement

The True RMS measurement method can measure
accurately the effective value of non-sine wave input
signal.

Average value measurement method can measure the
mean value of one sine wave input signal, and then
displays it as RMS value

When the input waveform has distortion, measuring
tolerance will be included.  The total tolerance depends
on the total distortion.  Below table 1 shows the waveform
coefficient and the relationship and the requested
changing factor of sine wave, square wave, pulse
rectangle wave, sawtooth triangle wave, RMS value
and average value.

Input Wave     PK-PK      0-PK       RMS        AVG

Sine

PK

0

PK-PK

sine commute
(whole wave)

PK

0

PK-PK

sine commute
(half wave)

PK

0

PK-PK

square wave

PK
0

PK-PK

commuted square wave

PK
0

PK-PK

pulse rectangle

X

0

PK-PK

Y

D=X/Y

sawtooth triangle

PK
0

PK-PK

2.828

1.414

2.828

1.800

1.800

0.9/D

3.600

1.414

1.414

2.828

0.900

1.800

0.9/ D

1.800

1.000

1.000

1.414

0.900

1.272

0.9D/2

1.038

0.900

0.900

0.900

0.900

0.900

0.9/D

0.900