"Monroe, of course..." > wrote in message
...
> In article >, "Jack
Curry"
> <Jack-Curry deletethis @cfl.rr.com> wrote:
> >
> > The wire is Type K thermocouple (it's a pair of alumel and chromel
wires
> > insulated with a very high temp teflon skin). The ends of the two
wires are
> > stripped and twisted together, or caused to weld together by using
a 12V
> > battery and a piece of carbon rod - either way works. The wire
comes in
> > varying gauges and therefore temperature resistances. The twisted
pair is
> > just jammed down into the end of an old Polder probe or any other
similar
> > stainless steel tube. It's not sealed in, since any glue or
sealant would
> > have to be high temp resistant and food safe at the same time.
The other
> > wire ends are fitted into a small male connector that plugs into
the Fluke
> > thermometer. Then you have an extremely accurate, very durable
nearly
> > instant read thermometer that can be inserted into meat or used to
measure
> > any temperature almost anywhere. BTW, Flukes are commonly used in
the air
> > conditioning industry.
> >
> You could seal the junction with a sploot of hi-temp RTV if you were
> planning to use the thing as a meat thermometer strictly-chromel is
NOT
> something you'd want in contact with your food.
> I use mine as a grilling temp indicator mostly - There is not any
TC
> readouts made yet that have an alarm feature. They make loggers and
> min/max data point storage but so far, no alarm function is
> available. These units are for industrial purposes, mainly.
> Like Jack said-the spot where the two wires first touch to make a
> circuit is where the temp is taken. The resistance across that
> particular spot where the differing metals meet is what determines
the
> temp. The teflon skin is not indestructable, though. If it burns
> through, you can create a new junction either by welding the wires
like
> Jack said or re-insulating the break or by cutting the wire back and
> twisting the ends to make a new probe end. You can't do that kind of
> repair to the polders-when they're dead, they're dead for keeps.
> I checked www.omega.com and they have single channel K-type handheld
> readouts for less than $70. You simply can't beat that with a
stick.
> I used these type units (in the real working world) to determine air
> temperatures for government spec pollution analysis work. They're
> tough, reliable, calibratable and better than just about anything
else
> available for the purpose.
> For Google research purposes here's some keywords: thermocouple, K
> type,chromel-alumel, handheld, Omega and Fluke.
> Not much works better (between -50F and 2200F that is)
>
> monroe(choir dismissed)


Thx for the input fellas. I have been kicking the idea of a
thermocouple around for a year or two. I'll give it a try this year.

TomD