Averaging times for RMS measurements
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A pure sine wave has Gaussian white noise added to it. The greater the
number of samples in the average, the more accurate the estimate of the RMS
value.
Experiment #1: Set the Sine Amplitude to 3, the Noise to 4 . According to the Pythagorean theorem, the result should be 5. Experiment with the number of samples to see how the result is affected.
Experiment #2: Set the Sine Amplitude to 1 and the Noise to 0.1. What should the RMS value be?
(1.005 is the right answer . . . verify it. Why is it only such a tiny increment above 1 V instead of 10 % above 1 V?)
Answer, the voltages are always added according to the Pythagorean Theorem, i.e. the square of the sum of the squares. Squaring small numbers such as 0.1 makes them much smaller, hence the tiny influence.
Filename: 1153.llb
Application Software: LabVIEW Full Development System 6.0
Language(s): LabVIEW
number of samples in the average, the more accurate the estimate of the RMS
value.
Experiment #1: Set the Sine Amplitude to 3, the Noise to 4 . According to the Pythagorean theorem, the result should be 5. Experiment with the number of samples to see how the result is affected.
Experiment #2: Set the Sine Amplitude to 1 and the Noise to 0.1. What should the RMS value be?
(1.005 is the right answer . . . verify it. Why is it only such a tiny increment above 1 V instead of 10 % above 1 V?)
Answer, the voltages are always added according to the Pythagorean Theorem, i.e. the square of the sum of the squares. Squaring small numbers such as 0.1 makes them much smaller, hence the tiny influence.
Requirements
Filename: 1153.llb
Software Requirements
Application Software: LabVIEW Full Development System 6.0
Language(s): LabVIEW
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