Gotta get my two cents worth in on this one.....
In the first place, a
Fluke is the
standard by which most other digital meters are judged. In electronics, and especially computers, there is
no better. The models with 4-1/2 digits and true RMS do particularly well in mill trouble shooting and calibration of 4-20 mA current loops. I have used them since they had Nixie tubes for the display and while slow, they were extremely accurate even then.
However, when dealing with motors and motor controls, nothing beats my
Simpson 260. Mine is a Series 4, a really archaic one, because this has been my mainstay meter since the 1960s. At only 20K ohms per volt, it will load the circuit enough to give accurate readings. So you don't need a battery. And don't get knocked off the bridge deck of a crane or off the mast of a ship.
It is
very important to know that the sensitivity of a Fluke is so high, several hundred K ohms per volt, that it will give a false, or seemingly false, indication in certain circumstances It could get you zapped, but more importantly, when troubleshooting it can give a false indication. As in
false test results..... I made repairs to a hard disk drive on Palau with a couple of light bulbs and sockets and a few pieces of wire. An old style CDC stand alone drive..... The tech I was bailing out was using a Fluke and couldn't make sense of the capacitor start motor with an electronic relay.(SCRs) He was getting false results...... (Verifiable at Pacific Data Systems, ca.1985)
I also use an older Micronta meter with the same impedence as the Simpson. It isn't near as rugged so I wouldn't want to drop it off an overhead crane. But I can trust the results and that's what counts.
BTW, this works for many high impedence electronics devices, even with gold plated contacts. Use a pencil eraser to polish the contact fingers. That will clear up many unanswerable questions. And a dollar bill to polish contacts. A fifty works even better but is harder to come by. Currency paper
is rather abrasive.
Although meters aren't specifically noted there, I posted a writing on
Home Shop Electrics a few years ago.
http://www.hudsontelcom.com/
Down the home page a little. It may prove useful.....
The ramblings of an old school electrician;
Bill Hudson