Damage caused by digital multimeter?

[Albm&ctd]

Heard a strange tale today. When a friend of mine went to buy a
digital multimeter, he was told that the cheap digital ones would
damage the computer in his vehicle. According to friend, salesmans
words were 'blow the computer'.
I'd never heard anything like that before and I figured this was
bullshit and the guy only wanted to sell their $125 one.

We were told in '84 that analogue was not to be used as it *may* harm
the new electronics, yet they supplied as a "special tool" a crude
test lamp consisting of a led and a resistor, a greater load than a
good analogue meter.
I thought most of the reason was to avoid odd readings with analogue
loading the circuit rather than cause damage?
Could be wrong...

Al
2004 insult page awaits your contribution
http://kwakakid.cjb.net/insult.html

 

[Franc Zabkar]

On Wed, 21 Jul 2004 06:08:42 GMT, alb_mandctdNOWMD@connexus.net.au
(Albm&ctd) put finger to keyboard and composed:

Heard a strange tale today. When a friend of mine went to buy a
digital multimeter, he was told that the cheap digital ones would
damage the computer in his vehicle. According to friend, salesmans
words were 'blow the computer'.
I'd never heard anything like that before and I figured this was
bullshit and the guy only wanted to sell their $125 one.

We were told in '84 that analogue was not to be used as it *may* harm
the new electronics, yet they supplied as a "special tool" a crude
test lamp consisting of a led and a resistor, a greater load than a
good analogue meter.
I thought most of the reason was to avoid odd readings with analogue
loading the circuit rather than cause damage?
Could be wrong...

The only thing that comes to mind in regard to automotive computers is
the EGO sensor. Apparently these devices can be damaged when using a
multimeter to measure their resistance. I don't know if this
disclaimer only applies to the multimeter's diode range.

http://members.rennlist.com/dan10101/docs/O2.doc

=======================================================================
Will testing the O2 sensor hurt it?

Almost always, the answer is no. You must be careful to not *apply*
voltage to the sensor, but measuring it's output voltage is not
harmful. As noted by other posters, a cheap voltmeter will not be
accurate, but will cause no damage. This is *not* true if you try to
measure the resistance of the sensor. Resistance measurements send
voltage into a circuit and check the amount returning (sic).
=======================================================================


- Franc Zabkar
--
Please remove one 's' from my address when replying by email.