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Old 11th June 2014, 02:07 PM
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Goran Goran is offline
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Just a little update on meters. Finally I understand how they calculate accuracy.
For my Kewtech 203 this means it is not very good for our application of measuring low currents below 1A,
http://www.kewtechcorp.com/sites/def...a_revamp_0.pdf
So it has a resolution of 0.01A, and accuracy of +-3% and 8 digits! Its this second part that' the killer

So if I am measuring a true current of 0.2A, the accuracy is 3% of this value + 8 digits of resolution, ie +-0.08, so accuracy is +-0.086, round up for resolution, +- 0.09
So that is why the display dances around because its resolution of 0.01A is way below its accuracy of +-0.09A
So if it displays 0.2A the true current could be anywhere between 0.11A to 0.29A. not very useful.

Article about accuracy and resolution:
http://www.aspowertechnologies.com/r...20Accuracy.pdf

Last edited by Goran; 11th June 2014 at 02:10 PM.
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