Dmm

[sqhertz 5,000+ posts]

Im suprized no one has done a write up on how to use/troule shoot a dmm. But theres a type argh thread haha.

On to my problem - I have never used a dmm before. Not even when i was an electricians apprentice. I just bought a craftsman 82082 from sears brand new.. i was going to find a better ground and set gains. went to touch the leads together and the numbers are going crazy (i have not touched them with my finger/skin). On the 200 ohm scale it was showing from 109.? down to .3 ohm. wtf? bad leads? i put them on rcas to see if theyre good, same thing , the numbers are jumping. //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

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[sqhertz 5,000+ posts]

anyone?

 

[sqhertz 5,000+ posts]

...someone has to know what its doing. i got it down to .3 ohm when i was absolutly still, but once i move it jumps all over the place.

anyone?

 

[disturbedfuel15 10+ year member]

What do you have it set to, AC or DC?

 

[sqhertz 5,000+ posts]

i had it on the 200 ohm scale. i need a dmm for today and tomorrow.

 

[sqhertz 5,000+ posts]

bump?

 

[sqhertz 5,000+ posts]

is that normal? anyone know?

amp is comming tomorrow and id like to check grounds/gains.

 

[sqhertz 5,000+ posts]

i think im going to return it and see what the next one does. from what i read/understood its not suppsed to fluctuate like that. but i dont know....

 

[xluben 10+ year member]

it's probably just such a small resistance it can't get a reading.

try touching the leads to your sub and it should give you something close to what the resistance is supposed to be.

or if you have a resistor lying around try measuring that.

 

[sqhertz 5,000+ posts]

ill try the sub thing tomorrow. ive just never heard/read of this happening. is it supposed to act like that? i tested some spare rca's i have and the same thing. unless im completly still the numbers are jumping. i dunno...

 

[sqhertz 5,000+ posts]

ok , i just put a 9v battery on the leads set to 20 vdc and it read 9.58-9.6 steadily. why would it do that crazy shit when set to ohms?? i NEED it today.

 

[sqhertz 5,000+ posts]

can anyone awnser that for me??

 

[sqhertz 5,000+ posts]

amp just got here. i need to know if i should return this dmm and get a new one.

ps: holly tape xluben haha.

 

[xluben 10+ year member]

glad the amp arrived!

yeah, i went a little nuts with the tape //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif i was thinking of just covering the whole box with it, but didn't go that far.

i'm 99.99999% sure that you're DMM can get a reading on such a small resistance. try it with the voice coils on your subs, or if you have any broken piece of electronics lying around just test one of the resistors.

 

[sqhertz 5,000+ posts]

no resistors or broken electronics here. from what ive read , like on the good ground sticky, when the leads are thouched together its suposed to read 0.0 - 0.3 ohms for good dmm leads. wtf is it jumping to 109.x for? odd.