> On Wed, 14 Aug 2002, Claudio Martin wrote:
>
> >Liquid is wine stored in tanks and the range of temp. is from 10 to 30
> >degrees. Regarding the response time isn't that important, because it's a
> >huge mass of liquid. I have to check the temperature at a point located at
> >the center of the mass of liquid. This point is about 3 meter from the top
> >cover of the tank. I guess one stainless steel tube could be a good
> >solution, but one point to work out is how to keep the sensor in contact
> >with the end of the tube, is there any kind of glue with a good thermal
> >conductive coeficient?.


Wine is acidic, so it's probably best not to use
a metal tube. Get plastic tube rated for the food
industry, and I would use a non-toxic heatsinking
grease like petroleum jelly in case of any leakage.
The thermal mass of the wine is very large and the
rate of temperature change will be slow, so the
thermal sensor does not need any special treatment,
ie anything buried in a 3 meter radius of water is
going to be at the average temp! :o)

I would also suspect that this being mainly water
with normal convection etc the temperature in the
middle probably won't be that much different than
near the edges of the tank. You may just be able to
put the probe near the tank wall (only about 30cm
in?) and be close enough in temp.

Be aware that there may be laws/standards related
to the materials you can immerse in a food product...
-Roman

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads