Applications 4

True RMS Measurements

 

 

PEAK VOLTAGES

METERED VOLTAGES

DC AND AC

AC-COUPLED

 

 

AC COMPONENT ONLY

DC

TOTAL RMS

INPUT

 

 

 

 

TRUE RMS =

PK-PK

0-PK

 

 

COMPONENT

WAVEFORM

RMS CAL*

FLUKE 45

 

 

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 METERS THAT ARE CALIBRATED TO DISPLAY RMS FOR SINE WAVES

aam18f.eps

Figure 4-3. Waveform Comparison Chart

4-11

Page 55
Image 55
Fluke 45 user manual True RMS Measurements

45 specifications

The Fluke 45 is a versatile and high-precision Digital Multimeter that is designed for a wide range of applications in electrical testing, troubleshooting, and maintenance. Known for its reliability and advanced features, the Fluke 45 is an essential tool for engineers, technicians, and professionals who require accurate measurement capabilities.

One of the standout features of the Fluke 45 is its ability to measure both AC and DC voltage and current. With a maximum input voltage of 1000 volts and current ranges up to 10 amps, users can conduct a variety of electrical tests with confidence. The device is equipped with an intuitive dual display, allowing for simultaneous viewing of multiple measurements. This feature enhances usability during complex diagnostics.

The Fluke 45 also boasts an impressive resolution of 0.1 mV and a basic accuracy of 0.25%, which translates to highly reliable readings. The auto-ranging capability simplifies the measurement process, automatically selecting the appropriate range based on the input signal, thus saving time and reducing user error.

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In summary, the Fluke 45 Digital Multimeter is an advanced instrument that combines precision, versatility, and user-friendly design. Its wide measurement capabilities, high accuracy, and durable build make it an invaluable tool for professionals in diverse electrical and electronic applications. Whether for routine maintenance or complex troubleshooting, the Fluke 45 stands out as a reliable partner in achieving accurate and efficient results.