Does anyone know how to calibrate this? Made in the UK.
black star multimeter 3225
Oct 10, 2007
6 Replies
First you sit down and eat your tea and crumpets. then you complain about the price of petrol. then you complain about the Americans. ( that is if you are a Brit to start with). and after all of that. if you still have interest in calibrating that meter. You could then start looking at the manual. personally, I don't thing the meter should nerd calibrating. If so, and you're looking for very high accuracy? I don't think you should be doing it.
Over here in good old USA. a Simpson 260 Analog meter is considered a standard. Or at least, it once was. ( I have one btw, in very good condition)
"I'm never wrong, once i thought i was, but was mistaken"
Real Programmers Do things like this.
http://webpages.charter.net/jamie_5
Ah another helpful American ;-)
The point is that I have a class of students that must calibrate a piece of electronic equipment according to the manufacturer's instructions. We have lots of these meters and since they are battery driven they are safe to dismantle. I was hoping someone has done this.
Well, if you really want to "calibrate a piece of electronic equipment according to the manufacturer's instructions" thenyou need to get those instructions. And since you are referring to a mass production unit, any calibrating (pot tweaking) done at the factory is done according to
*internal* methods and thus is !proprietaty! and will not be disclosed. So, the best you can do in this case is "calibrate a piece of electronic equipment according to best (to be determined) efforts". Take one apart and tweak only one pot at a time, say by only one screwdriver blade-width, and check all scales to find what changed. This way, each adjustment can be labelled "capacitance zero", "resistance", "voltage", "unknown". *RESET* the tweak when done. Use a digital camera for a closeup and label the photo (use arrows to pots) accordingly; print copies along with a suggested procedure that you determine. You can use 0.1% resistors and 2% capacitors as "standards", along with an off-the shelf precision voltage regulator. Current measurements are never adjustable; they depend on the internal shunt accuracy and voltage measurement accuracy.
Ok, well, I do remember (years ago no when I was a kid), a fresh carbon cell was to output something like 1.56xxx , I can't remember exactly. but that was the calibrator. Now days, I really don't think they do that any more.:) Sorry I couldn't of been any more help to you.
"I'm never wrong, once i thought i was, but was mistaken"
Real Programmers Do things like this.
http://webpages.charter.net/jamie_5
Thanks.
No, no, no! Mercury cells were good enough to use as a secondary standard when calibrated, and if not, new ones wer good to 5 digits (if i remember correctly - been ages).
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