As others indicated, if you were on DC
current, that is basically a short
circuit. Most, if not all meters have a
fuse inside to protect against just
that type of thing. If the fuse is now
open, the meter will still work on
AC and DC volts, and ohms scales, just
not on current settings. BTW,
if you use a multimeter a lot, changing
scales, etc., this is a pretty common
thing to happen.

timO' wrote:
On Feb 24, 6:52 am, wrote:
On 23 Feb 2007 16:33:13 -0800, wrote:

I mistakenly left my digital multimeter on DC when i went to test a
wall outlet, and it threw a spark and charred the tips of my
multimeter. I had always been told it would not do such a thing, even
on the wrong setting. However, I am now timid to recheck the outlet
on the AC setting. So, I used a outlet plug light indicator and it
said everything was kosher with the outlet. Can anyone tell me why
the spark?
Tom
It shouldn't spark at all. If the multimeter is of any decent design
it should have a high ohm/volt rating and should not present a
meaningful load to a circuit even on DC.

Did you rotate the switch while connected? Did you fumble one of
the leads? Did you have it on current?

I agree, in the DC mode, there shouldn't have been sparks. did the
meter have autorange? If you are concerned that the meter is mdamaged
and do not want a repeat spark event; try checking the meter against
itself in the ohms setting, or measuring a 1.5 battery, or a low
voltage AC source such as a no longer needed wall wart from an old
cell phone.
If the wall receptacle had a metal plate on it, you might have also
accidentally shorted a lead against it.
I suppose that if you do not use a meter on a regular basis, you would
purchase the least expensive one you could find, and you consequently
would also have minimal experience making measurements; if you use a
meter on a regular basis, you know that having a good quality meter is
imperative for safety and accuracy, and you also have expertise in
taking measurements. If you cooked your meter, and did not stop your
heart, then you paid a small price for a valuable lesson in taking
measurments safely, and selecting higher quality when shopping for a
new meter.
hope this helps