Chronology | Current Month | Current Thread | Current Date |
[Year List] [Month List (current year)] | [Date Index] [Thread Index] | [Thread Prev] [Thread Next] | [Date Prev] [Date Next] |
in research 2ppm is common -- A Sr. thesis student at UCSC
recently built who study critical effects use these things.
Vernier's has (in your range of interest) 0.03 C deg. resolution.
http://www.vernier.com/probes/temp.html
Ten strokes ~ 15% resolution, a hundred -- 2% -- "doable".
Ludwik Kowalski wrote:
kyle forinash asked:
Does anyone have a simple mechanical equivalent of heat
laboratory exercise (1st year undergrad level)?
I know of two; lead shot falling in a tube (which has horrible
accuracy) and the 'calorimeter on a crank' appratus (pretty
costly). I don't like either. ...
Somebody who has access to a shop can produce something
like this. It is a sealed iron tube (3 kg) and an iron piston (10 kg)
inside, with some air. The piston can travel 1 meter from one
end to another; it has holes allowing air to sip during a vertical
fall. Suppose the tube, well insulated with styrofoam, has a
mechanical release system to trigger the fall of the piston. By how
much should the temperature increase? PE decreases by 98 J
producing 23.4 calories of heat. Assuming all of it goes to 13
kg of iron the expected dT is 0.018 degree (in a single shot).
Can such dT be measured with a thermister to within ~1%
accuracy? I do not know.