Remove the caps, smash it, grind it to dust, and then analyze it in a mass
spectrometer.
Or perhaps put a meter on it, and/or just replace it?
I do that too, but it very much depends on the application voltage and
available current. Mains fuses can nicely metalize the glass under
high fault currents, whereas a similar current at 12V will simply melt
the fuse wire. 500mA is a fairly hefty fuse and the wire should be
visible or it should have left some indicators.
Neil S.
If the fuse came out of a new box maybe it was made faulty?
--
Boris
If the fuse wire was tin, it may have evaporated and then oxidized.
Tin oxide is transparent.
Interesting. Has tin been used in fuses? I toured a company that makes
fuses for utility companies and they only use silver wire. I asked why and
the answer was nothing else is as reliable or ages like silver.
I've been fascinated by cheapo fuses that on the box claim to be
"electronically tested", whatever that means for a fuse that was probably
made by school children.
>
>I've been fascinated by cheapo fuses that on the box claim to be
>"electronically tested", whatever that means for a fuse ...
It means that they put an ohms meter or continuity tester on it and it
read shorted.
shorted?
A 10mA fuse (yes they do exist I have some in front of me)can easily measure
more than 100 ohm, pro rata for more worldly fuse ratings . Measuring of
ohmage probably gives a go/no go for rupture current.