Analog multi-meter oops
Thread Starter
Pro
Joined: May 2002
Posts: 726
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From: Petaluma CA
Analog multi-meter oops
After test several electricals on the 81 a friend mentioned that resistors in the computer can be blown by an analog meter...oops. Everything seems OK, but I had never heard that...time to go tool shopping...
Pro
Joined: Nov 2000
Posts: 582
Likes: 1
From: Madison Wisconsin
Re: Analog multi-meter oops (Stevo)
Stevo;
I do not believe this is true, resisters do just that resist electricity the amount of power coming from a volt/ohm meter is so small it makes it almost imposable. I am an aircraft technician and I test computers far more complex and sensitive than automotive computers and have not burned one up yet. If any thing I find that a digital meter will induce stray voltage in to a circuit when testing an airframe for micro volts
I do not believe this is true, resisters do just that resist electricity the amount of power coming from a volt/ohm meter is so small it makes it almost imposable. I am an aircraft technician and I test computers far more complex and sensitive than automotive computers and have not burned one up yet. If any thing I find that a digital meter will induce stray voltage in to a circuit when testing an airframe for micro volts
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
Re: Analog multi-meter oops (Stevo)
NO, it would have to be a highly unusual situation, so unusual that it ain't a gonna happen....
now at one time in a chip's life it can be blown by such things, but when it's mounted on a card, and the card is complete, the input gates are held neutral by much lower resistances than they would have open circuit....so handling is not an issue....
NOW having said that....STATIC discharge will allways be an issue, that's why most automotive computers are in an aluminum box....the wiring from the loads/sending units is too low an impedance to be a threat....
I also suggest that most aircraft are in a high EMI environmnet, and as such it's the DVM LEADS putting signals into wiring acting as an antenna....have to use something shielded, like a scope probe, should cut down alot on that...
GENE
now at one time in a chip's life it can be blown by such things, but when it's mounted on a card, and the card is complete, the input gates are held neutral by much lower resistances than they would have open circuit....so handling is not an issue....
NOW having said that....STATIC discharge will allways be an issue, that's why most automotive computers are in an aluminum box....the wiring from the loads/sending units is too low an impedance to be a threat....
I also suggest that most aircraft are in a high EMI environmnet, and as such it's the DVM LEADS putting signals into wiring acting as an antenna....have to use something shielded, like a scope probe, should cut down alot on that...
GENE
Racer
Joined: Jul 2001
Posts: 264
Likes: 0
From: Maricopa AZ
Re: Analog multi-meter oops (mrvette)
Buy a Fluke meter. They cost more but they are the best meter out there and they can be fixed or recalibated with no problems. If you dont need to read amps Id get the Fluke 12 meter.
