True-RMS Measurements

Waveform Comparison (True RMS vs Average Responding) C

 

 

PEAK VOLTAGES

MEASURED VOLTAGES

DC AND AC

AC-COUPLED

 

 

AC COMPONENT ONLY

DC

TOTAL RMS

INPUT

 

 

 

 

TRUE RMS =

PK-PK

0-PK

 

 

COMPONENT

WAVEFORM

RMS CAL*

HYDRA

 

 

ONLY

ac

2

+ dc

2

 

 

 

 

 

 

 

 

 

 

 

 

 

SINE

 

2.828

 

 

 

 

 

 

 

 

 

 

1.414

 

 

 

 

 

 

 

PK

 

 

 

 

 

 

 

 

 

 

 

 

1.000

 

 

 

 

 

 

 

PK-PK

 

 

 

 

 

 

 

 

0

 

 

 

1.000

 

 

 

 

 

 

 

 

 

 

 

0.000

 

 

 

 

 

 

 

 

 

 

 

1.000

 

RECTIFIED SINE

1.414

 

 

 

 

 

 

 

 

(FULL WAVE)

 

 

 

 

 

 

 

 

 

1.414

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PK

 

 

 

0.421

0.436

 

 

 

 

 

PK-PK

 

 

 

0.900

 

 

 

 

0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1.000

 

 

 

 

 

 

 

 

 

RECTIFIED SINE

2.000

 

 

 

 

 

 

 

 

(HALF WAVE)

 

2.000

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0.779

 

 

 

 

 

 

PK

PK-PK

 

 

 

0.771

0.636

 

 

 

 

0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1.000

 

 

 

 

 

 

 

 

 

SQUARE

 

2.000

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PK

 

 

1.000

1.111

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1.000

 

 

 

 

 

0

PK-PK

 

 

 

 

 

 

 

 

 

 

 

 

0.000

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1.000

 

RECTIFIED

 

1.414

 

 

 

 

 

 

 

 

SQUARE

 

1.414

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0.785

 

 

 

 

 

 

PK-PK

 

 

0.707

 

 

 

 

 

 

 

 

 

 

 

 

 

PK

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0.707

 

 

 

 

 

 

 

 

 

 

1.000

 

0

 

 

 

 

 

 

 

RECTANGULAR

2.000

 

 

 

 

 

 

 

 

PULSE

 

 

 

 

 

 

 

 

 

 

 

2.000

 

 

 

 

 

 

 

PK

 

 

 

 

 

 

 

 

 

 

 

 

4.442 K2

 

 

 

 

 

 

0 X

PK-PK

 

 

2K

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Y

 

 

 

 

 

2D

 

 

 

 

D = X/Y

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2

D

 

K = D-D2

 

 

 

 

 

 

 

 

 

TRIANGLE

 

3.464

 

 

 

 

 

 

 

 

SAWTOOTH

 

1.732

 

 

 

 

 

 

 

PK

 

 

0.962

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1.000

 

 

 

 

 

0

PK-PK

 

 

 

0.000

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1.000

 

 

 

 

 

 

 

 

 

* RMS CAL IS THE DISPLAYED VALUE FOR AVERAGE RESPONDING INSTRUMENTS THAT ARE CALIBRATED

TO DISPLAY RMS FOR SINE WAVES

Figure C-1. Comparison of Common Waveforms

C-3

Page 243
Image 243
Fluke 2640A, 2645A user manual True-RMS Measurements

2645A, 2640A specifications

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