Forum Discussion
- MEXICOWANDERERExplorerError is normally based on the range selected
3% + - 6
On a 100.0 range setting
% = 97.0 to 103.0
at one hundred amps reading, 100.0 on the dial
plus minus six digits 97.0 minus 6 = 96.4
to plus 103.6
Now, do you see why I squawk about my 5 digit voltmeters? 1.5% error = - 3 digits.
The cheapo Bang Good clamp on ammeter I have reads up to 40.00 on low scale and it is FAR more accurate than the hurricane destroyed Triplett that cost three times as much.
One amp resolution is fine for me at 500 amperes. - Snowman9000ExplorerSo what is the error range for a reading of 1 amp? Depends on the decimal places after the 1?
- DrewEExplorer II
2oldman wrote:
Then shouldn't it be ±6?
The +/- applies to both the 3% (of the reading) and the 6 counts. In other words, it's +/- (3% plus 6 counts); for readings that are well lower than full scale, the 6 counts could easily be a much greater error than the 3%. - ktmrfsExplorer II
2oldman wrote:
Then shouldn't it be ±6?
no.
OK, a good digital meter will have spec reading something like
+/- X% of reading +/- Z counts
E.G. +/- 2% +/- 6 counts
usually AC accuracy is worse than DC accuracy,
For AC accuracy a frequency range and crest factor range is usually specified. Crest Factor= Peak to RMS ratio. Crest factor for a pure sine wave is 1.414. The peak voltage is 1.414 times the RMS value. Square wave centered on 0V has a crest factor is 1. - wa8yxmExplorer IIITo me it means it may round UP on 4
IEL 20,4 anps might show as 21 amps. - MEXICOWANDERERExplorerGotta remember these ads are formulated by folks who understand
I have a cheap digital meter I purchased from BANG GOOD and it works great. The 40 amp DC scale measures amperage like 16.36 so the least significant digit is truthfully not significant - 2oldmanExplorer IIThen shouldn't it be ±6?
- westendExplorerRange of tolerance with the last significant number having a tolerance spread up to 6.
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