whit3rd wrote:
On Sep 28, 12:39?am, "N_Cook" wrote:
Where cause is unknown I closely inspect fuses to gauge whether
mechanical/aging or thermal failure and then an idea of rupture current.
This ELU 20mm 500mA F fuse had no trace of the wire , no smoke stain or
hazing at all in the glass tube. I cracked the glass expecting to see
remnants of wires or powder or something in the ends but nothing...

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.