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Simple multimeter question.


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Hi,
I found this site using Google, and I've got a really simple question to ask. I'm just beginning to get into electronics and stuff, so I may be visiting this site regularly!

First of all, I aquired this analogue multimeter, but I'm doubting it's accuracy. It doesn't seem to read the voltage of anything right. But then I noticed there's a quite large sized screw that you can adjust the needle with, so it probably (actually, I'm POSITIVE) it needs calibrating.

The question is; HOW do I go about calibrating it? I'm thinking I'd just stick it in a wall outlet, and calibrate the AC to 120V, but then again, I have no idea if my outlet is really putting out 120V (is this right? I don't really know if there's any deviation from a 120V wall outlet, or if an outlet ALWAYS puts out exactly 120V.)

I really need to know, since my computer's motherboard and GPU gave out recently, and I'm wondering if it's because of the power supply. I tried reading the 12V rail, and it read as around 11.25V (Which definately isn't normal, 12V rail should deviate +/-5% at most). But, again, I don't think that's right, as the multimeter requires calibrating.

Anyone? Also, do you think the battery life would have any effect?

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Why bother with an analog meter? Digital meters are available for a few $'s that will have orders of magnitude better accuracy than an analog meter. Analog meters usually have fixed 1% or slightly better custom value resistors in their divider circuits which makes any calibration difficult. Even the cheapest digital multimeters use laser trimmed resistances and good voltage references today.

I grew up with analog meters and have collected about a dozen of them. They are now collector items. I will never sell them, or use them for any serious measurements. Also analog meters will give different readings laying flat or standing up.

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Learning how to use an analog meter is essential, understanding the multi-ranges will provide a keen experience concerning other measuring devices.

Example:
Remember, learning boolean algebra as applied to digital circuits?
The calculations as to how they were applied seemed somewhat vague.
However,  once the above is applied into its useable form concerning (gate fashion) it all made sense!
The above measure of understanding allows more advanced expressions to visualize.

One can look at an analog meter from a similar perspective.

I have an assortment of digital meters but always keep my Simpson 260 at reach.
Being able to view a basic RC time constant is a lot more practical when using the analog variety.
Viewing first hand the linear swing of a movement is very satisfying.  ;)

-Omni

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"I'm just beginning to get into electronics and stuff, so I may be visiting this site regularly!"

What part of the above sentence do you not understand?


A functional VOM (analog) is usually a part of every test bench, since the above individual is new to electronics learning to use an analog meter with multi-ranges will only increase his versatile envolvement.

Accuracy concerning a meter is determined by the individual reading the movement.
Although, the meter he described may have a few issues the latter is a great place to start concerning a first project for troubleshooting.


-Omni

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