Rms Versus P-P Amplitude - Fluke 522A/6 Operator's Manual

5522A
Operators Manual

RMS Versus p-p Amplitude

The Calibrator ranges for sinusoidal ac functions are specified in rms (root-mean-square;
the effective value of the wave form). For example, 1.0 to 32.999 mV, 33 to 329.999 mV,
0.33 to 3.29999 V and so forth. The sine wave outputs are in rms, while the triangle
wave, square wave, and truncated sine wave outputs are in p-p. The relationship between
p-p and rms for the non-sine wave types are as follows:
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•
•
While the ac function ranges are directly compatible for sine waves, the rms content of
the other waveforms is less apparent. This characteristic leads to subtle calibrator range
changes. For example, if you enter a sine wave voltage of 6 V (rms assumed), the
selected range is 3.3 to 32.9999 V. If you then use the softkeys to change from a sine
wave to a triangle wave, for example, the display changes from 6 V rms to 6 V p-p. This
translates to 6 V p-p x 0.2886751 = 1.73205 V rms, and the range switches to 0.33 to
3.29999 V. The Output Display shows the range change because the sine wave voltage is
displayed as 6.0000, the resolution for the 3.3 to 32.9999 V range, while the triangle
wave is displayed as 6.00000, the resolution for the 0.33 to 3.29999 V range.
You need to know the active range to enter the correct values for voltage offset because
the maximum offsets are range specific. For example, the maximum peak signal for the
3.3 to 32.9999 V range is 55 V while the maximum peak signal for the 0.33 to 3.29999 V
range is 8 V. This means in the example above, the 6 V rms sine wave could have offsets
applied up to the maximum peak signal of 55 V because the active range is 3.3 to
32.9999 V, while the 6 V p-p triangle wave could have offsets applied up to the
maximum peak signal of 8 V because the active range is 0.93 to 9.29999 V. See
"Specifications" in Chapter 1 and "Entering a DC Offset" later in this chapter for more
information about dc offset voltages.
4-16
51
K/J THERMOMETER
ON/OFF
F/C
HOLD
OFFSET !
60V
24V
MAX
Connection wiring must match thermocouple type, e.g., K, J, etc.
Figure 4-10. UUT Connection: Temperature (Thermocouple)
Square wave p-p x 0.5000000 = rms
Triangle wave p-p x 0.2886751 = rms
Truncated Sine wave p-p x 0.2165063 = rms
5522A CALIBRATOR
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