Multimeters

WyoTraveler wrote:
I would believe the Fluke meter. John M. Fluke made some good meters.

X2

Fluke is a well established test equipment manufacturer, specializing in high tech equipment. Their oldest engineer, second in seniority to John Fluke was a friend of ours. He passed away over 20 years ago but I still remember him talking about the accuracy of their test equipment.

Four Meters - Fluke 88, Tektronix DMM150, Harbor Freight (freebie), Hampton Watt meter. I used the same Fluke test leads on all meters.

High voltage AC:









Low voltage DC:

Fluke 88



Tektronix DMM150



Harbor Freight

If you download the owner's manuals for your meter there is a section called "Specifications" and in it is gives the accuracy of the meter. +/- N% where N is the accuracy.

4 volts is less than 4% and what's more it is +/- less than 2% of the same number, USUALLY this is well within the acceptable error for a low cost meter.

Now I have used some serious. Lab calibrated, meters (in college) and for those the error is a tiny fraction of a percent.. But you calibrate before every use.

What is more important than accuracy is repeatability.. Given the same source voltage, will the meter read the same time and time again.,

Interesting info, thanks for the input.
Joe

What ktmrfs says is exactly correct!

If two meters read the same it is a "Fluke"

" These calibration tools can cost tens of thousands of $$ each"

I got mine at at garage sale for eighty-seven-thousand-seven-hundred-dollars. a bid. It is the size of an old obsolete 23" television. It itself is calibrated by using N.I.S.T certification resistors one, ten, one hundred and 10K ohms. Interesting devices, the test probes, and connectors are gold clad. Products of Sandia National Laboratories. Using this stuff teaches the meaning of the word "Null" in a hurry :)

PS: A handheld nickel and dime "scope meter" has obsoleted the monster. I loaned this thing out back in 1997 and have never seen it nor the borrower since.

TIP: And it's a good one. A decent 4-3/4 digit DMM offers accuracy good enough even for technicians. These critters are getting less and less expensive.

For us cheapskates, there's a 0.01% DC reference available for $25.50 Voltage Reference, Model VREF-01. If that's too much, an LT1009CZ Voltage Reference Diode provides 0.2% accuracy for less than 2 bucks.

For us electrical control freaks, that Voltage Reference, Model VREF-01 is like holding out a sack of "China White" in front of a junkie. Thanks for the link!