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dmm questions

Printed From: the12volt.com
Forum Name: General Discussion
Forum Discription: General Mobile Electronics Questions and Answers
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=37922
Printed Date: May 03, 2025 at 6:52 AM


Topic: dmm questions

Posted By: bigblackhoe
Subject: dmm questions
Date Posted: August 22, 2004 at 10:44 PM

ok so in a moment of stupidity i bought a cheap 20 dollar dmm from advance auto parts. its the kind with two probes...how do i use this thing? and also, it says that its 10 amp max....are there any dmm's that can take more than 10 amps?



Replies:

Posted By: Teken
Date Posted: August 22, 2004 at 11:07 PM
I would ask you to read the enclosed manual as a starter.

Second, if there is a specific Q you need answered, please be specific about what you need clarified.

Third, most consumer DMM's are rated for 10 amps maximum, some are rated for 20 amps.

Forth, the DMM you purchased is just fine for what you are doing for the *shade tree mech*

If you have limited knowledge of electronics, or electricity, I would urge you to take some time to read over the basics.

Then practice some of that knowledge on small projects.

ie. Take voltage measurements from your battery, house outlet, etc.


Regards

EVIL Teken . . .




Posted By: bigblackhoe
Date Posted: August 23, 2004 at 3:44 PM
yeah i read the manual and all i guess the only two questions i have are this: do i just touch the negative probe to any ground? and also: so if its 10 or 20 amp max i couldnt take any measurements from my amps power wire for example?




Posted By: Teken
Date Posted: August 23, 2004 at 4:59 PM
bigblackhoe wrote:

do i just touch the negative probe to any ground?


Yes . . . But specificly you will touch / attach the negative probe to a paint free / clean metal surface area. Otherwise the DMM's display will either fluctuate, or display a incorrect reading.


bigblackhoe wrote:

so if its 10 or 20 amp max i couldnt take any measurements from my amps power wire for example?


No, that is correct. If you wanted to do that you could purchase a clamp on meter, which is sometimes called a *tong testor.

The last resort is to use / apply a shunt. If you have any further Q's please do ask.

Regards

EVIL Teken . . .




Posted By: flynntech
Date Posted: August 30, 2004 at 6:38 AM

Don't sweat it, $20 meters are fine. I have a craftsmen meter that costs about that much and it works great. I got it for free when I was in school. When I was installing, the other installers ridiculed it and said I needed a fluke. It's funny because this meter is accurate within 1% of a $400 fluke. I'm not saying flukes aren't good meters, but for mobile electronics and most anything else, anything will do as long as it's not totally cheezy cheap.

I work on electronics for a living and we use anything from the 'generic specials' to $2000 Flukes which are very accurate to .000001 volts, perfect for a cal lab...but way overkill for almost anything else.

Please learn the basics of electron movement before you start fooling around with a mutimeter, sticking it an AC outlet and so forth. As Teken mentioned, the clamp meter is better for measuring high currents, much safer and some are very accurate. 






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