Sir Charles W. Shults III:
That is a good in depth, overly complicated, answer but not the one I was
looking for..... obviously since the Tim Williams posting said ".And
besides that, it measures actual in-circuit conditions, because a resistor
is *supposed* to get hot, at least if it's doing its job..." ..... and
since the overly discussed "2 meters and power supply" ohm meter method can
overheat low-ohm resistors..... and the resistance of any resistor will vary
with temperature..... I was wondering at what exact "hot" temperature the
resistor should be at to make an accurate measurement..... LOL
Obviously I am not looking for any kind of answer here....... I just think
that this thread went bonkers when all the original poster wanted to do is,
as Chuck Harris indicated in his reply post, show off his new found
factoid.... however it seems clear that it may not be a very practical and
convenient method as evidenced by the length and tone of the majority of the
reply posts.
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
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"Sir Charles W. Shults III" wrote in message
. com...
How hot? One solution is P=EI, where power in watts is equal to the
product
of voltage and current. So the voltage drop across the resistor
multiplied by
the current in amps through the resistor will yield watts of heat created
by the
resistor.
Now, if you know the composition of the resistor, you can look up the
specific heat of the material and calculate how much energy it takes to
change
its temperature. You will need to know how many joules of energy have
been
applied. Calculate the joules by multiplying the time that the power was
applied in seconds by the power in watts. Now look at the specific heat
table
and it will tell you how many joules per Kelvin it takes to raise the
temperature.
If you have any physics experience, it will be very simple.

Cheers!

Chip Shults
My robotics, space and CGI web page - http://home.cfl.rr.com/aichip