On Thu, 13 Oct 2005 12:30:44 -0400, Spehro Pefhany
wrote:

On Thu, 13 Oct 2005 16:10:37 GMT, the renowned "Dan Hollands"
wrote:

To know how difficult it is to get 0.1 degree accuracy one must know the
temperature range to be measured and the ambient temperature range for the
equipment doing the measuring. This also determines the resolution required
of the ADC.

In my experience achieving this accuracy is not easy and not cheap.

Dan

Yes. Getting 0.1°C *resolution* is easy and cheap (even with a
relatively low-level sensor like a thermocouple).

Getting 0.1°C accuracy is not easy and not cheap, and it only gets
worse the further you move from the ideal
fully-immersed-in-benign-liquid "CSTR" type of situation.

When i was an apprentice so long ago, I remember the company i worked
for using one junction of a transistor for doing 0.1degC. Accuracy was
actually a lot better, but thats all they could claim becasue of the
equipment used for calibration.

I remember that everytime they got a new batch of transistors, i would
have to spend days with an old 4wire thermistor and meter to make
readings every 0.05degC. Sitting with an ice bath waiting for the ice
to melt and trying to zero that meter was a right pain in the arse.
Calibrating the standard device was the same, and that had to be done
every three months.