[sdiy] resistor temperature coefficient measurement

[Czech Martin]

Yesterday I thought I could look into the (unwanted)
temperature dependency of some resistors.
I took some metal film types out of the box (speced to
+- 50 ppm) and measured the resistance at room temperature
and with coolant spray. To my surprise the resistance 
did not change in the first 5 digits, but the temperature
dropped certainly by 30 degrees C.

Perhaps the +-50ppm spec is the maximum deviation
that some production lots may have on a bad day
and the average is much better than this?

Any experiences or comments?

I will do this again with more time.

m.c.