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
