Jumpy dmm readings, clean the probes and connections maybe

Locrian99

Locrian99

Well-known member
So ive been having this problem somehwhat but not nearly as impactfully as it was last night as inwas trying to bias some power tubes i was having an awful time with my meter jumping around. Start at 499.x go down to 496, junp up to 502. Not helpful for trying to bias tubes.

I was thinking id try today cleaning the probes with some deoxit as well as the connectors where the probes plug in. Anything else to try?

Also debating finally buying a fluke.
 
I had this problem a while back. This could just be my own brand of doofus, but it occurred to me that the power cable to my soldering iron and the cables to my DMM probes were a little too close to each other. That, plus getting a little better at holding it steady and finding a solid connection.
 
Whatcha using right now?

Measuring equipment needs to be used with the understanding the potential pitfalls of the measuring equipment itself.

Greater resolution can give a false sense of accuracy, but simply being more precise does not mean that a piece of equipment is more accurate.

Whatever number appears in the screen is *always* going to be representative of a range of values, even on a Fluke.

I use an 87V: The 87V has a DC voltage accuracy rating of +/-(0.05%+1). That means that, should I be looking to dial in a measurement of 496Vdc, the actual voltage could be anywhere from 497.248Vdc to 494.742Vdc. Pretty good! Better be for how much the damned thing costs.

But it illustrates my point: the value that shows up on the screen is almost *never* the *actual* value. It's representative of a *range* of values.

I recommend taking a look at the published specs of your meter for the measurements you're trying to take. See if your comfortable with the range stated for the measurements you're taking.
 
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