>>But, radiation and convection may be significant contributors
>>depending on a number of factors which may be poorly understood or
>>controlled here.

> I think they can be ignored for the purpose of getting an estimate =

> of the
> effect of the T/C under the presumed conditions (< 100=B0C).

Why?
That may be good advice. But, can you provide rough justification for =

it.
Holding the leads a small distance away from a hot component with thin =

leads will expose you to a much reduced temperature.
My intuitive feel is that if you had a small device with thin wires at =

approaching 100C then the lead conduction would be smallish but that =

if you placed a sensor (finger, tongue or arcane electronics) near but =

not touching it that you would sense substantial energy transfer.

Leads may be copper or (some may be surprised to find) steel.
Copper has a coefficient of thermal conductivity of about 390 W/m/k. =

Steel/iron leads will be about 5+ times lower conductivity than that.
Watts dissipation by lead heatsinking can be worked out from there.
Having copper or steel leads will greatly affect the result.
In the case of a thermocouple the leads will usually be neither copper =

nor steel.

The fact that PTC devices and other thermistors can have their =

thermal/resistance characteristics very substantially affected by eg =

adding a sleeve of heat shrink indicates that radiation and/or =

convection are significant factors.

For a black body thermal radiation Wattage =3D Kb x A x T^4   (Kb =3D =

5.7E-8 =3D Boltzmann's constant.)
Aaagh :-)
Calculator here

        http://infrared.als.lbl.gov/calculators/bb2001.html

Convection ...
Aaagh aaagh aagh
Now. If you can just tell us the Nusselt number of your thermistor ... =

;-)
This is an excellent overview but probably won't help provide =

numerical results.

        http://www.cheresources.com/convection.shtml


        Russell



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