Download presentation

Presentation is loading. Please wait.

Published byCasey Garbutt Modified over 3 years ago

1
CORRECTING RMS VALUE OF A SINE WAVEFORM SAMPLED DUE LIMITED NUMBER OF PERIODS AND DETERMINATE APERTURE TIME ON DMM Keywords: Digital Multimeter (DMM), Root Mean Square (RMS) Error, Sampling, Aperture Time, Number of Samples

2
NOMENCLATURE DC = direct current AC = alternating current A/D = analog-to-digital RMS = root-mean-square t a = aperture time t 0 = initial phase t a [T] = aperture time in percentage of a period F = frequency F s = sampling frequency n = number of samples ppm = part per million

3
ROOT MEAN SQUARE Sine waveform segments can be generated according to the following equation: y[i] = A· sin(t 0 [T] + F·360.0· i/F s ), for i = 0, 1, 2, …, n – 1. Sampling info: #s = t a [T]·NRDGS, F s = F·NRDGS. Initial phase can vary. From collected mean values, LabVIEW and Swerlein algorithm (implemented in DMM 3458A instruments) calculates RMS value of a signal waveform. The standard uncertainty associated with the RMS estimate depends on the waveform stability, harmonic content, and noise variance, was evaluated to be less than 5·10 -6 in the 1 - 1000 V and 1 - 100 Hz ranges.

4
t a [T]=0,125 and t 0 [T]=0,1

5
CORRECTING RMS – SIMULATION PART RMS’ = RMS + A·(1 – sinc (π·t a [T])) NRDGS0,020,040,060,080,1 510,979400,998411,000090,998750,99557 1001,012501,013041,009031,003710,99538 1501,014041,013851,012491,005400,99905 2001,002201,006341,006731,003920,99810 f = 100 Hzt a [T]

6
CORRECTING RMS – REAL DATA

7
Difference (RMS’’- RMS’) [ppm] t a [T]0,050,10,15 1. sequence13,320112,6495-610,262 2. sequence34,892035,2091-208,972 3. sequence38,647244,1362-361,246 4. sequence27,710757,5519-445,994 7 V range, 50 Hz

Similar presentations

OK

AC Fundamentals Chapter 15. Introduction 2 Alternating Current 3 Voltages of ac sources alternate in polarity and vary in magnitude Voltages produce.

AC Fundamentals Chapter 15. Introduction 2 Alternating Current 3 Voltages of ac sources alternate in polarity and vary in magnitude Voltages produce.

© 2018 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Ppt on advance payment of tax Mba presentation ppt on functions of management Ppt on shell scripting basics Convert doc file to ppt online reader Ppt on semi solid casting Ppt on cross-sectional study definition Ppt on review of literature examples Ppt on earthquake in nepal 2015 Ppt on thermal conductivity of insulating powder coat Ppt on information system audit