Joseph Herbert on thu 4 mar 04
If you want to calibrate a pyrometer cones, which measure the mythical
quantity called heat work, are probably not very useful. There are many
alloys available in wire form that have a relatively well defined and well
known melting point. If you were to make little saucers with support posts
for a piece of wire, you could observe the sag and failure of a strand of
wire of known composition. when the wire sags and fails, the temperature in
the kiln should be close to the melting point of the alloy. As in the case
of cones, a really rapid temperature ramp up rate would not allow the alloy
to melt before the thermocouple reading was higher.
Where are the mystery alloy wires found - they are solders and brazing
alloys. They have a melting range from something like 350 degrees to over
2000 degrees F.
Joseph Herbert
Ivor and Olive Lewis on sat 6 mar 04
Dear Joseph,
Great idea.
For anyone wishing to follow this through the following lists some
very common metals which might prove useful to people. I would be
careful about Solders. Most incorporate a Eutectic or they have a
solidus and liquidus, temperatures at which melting commences and is
completed.
All values are Celsius and given to three or four figures.
aluminium 660
antimony 630
bismuth 211
cadmium 321
cobalt 1497
copper 1084 (could be very useful but coat with borax flux)
gold 1064
indium 156
lead 317
silver 961
tin 231
tungsten 3387 (for Phil in El Ve)
platinum 1772
Nickel 1 455
palladium 1554
Rhodium 1963
Zinc 419
<< If you want to calibrate a pyrometer cones, which measure the
mythical quantity called heat work, >>
I like it. I like it. Unless the folk who insist on using the term are
measuring Joules per Joule it really is a tautology.
Best regards,
Ivor Lewis. Redhill, South Australia
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