Here I checked five temperature measuring devices with melting snow.
The best is that is converts to slush by adding some tap water.
The values measured are:
1. Mercury thermometer -10-250oC : 0oC
2. Mercury thermometer -10-150oC : -0.5oC
3. Meat bimetal thermometer 0-100oC : -1oC
4. Type K thermocouple provided with an infrared thermometer:+1.8oC
5. Type K probe connected to a multimeter with type K readout: +0.9oC
So the deviatons are not negligible. I had to push the slush to keep contact with the five sensors.
EDIT: I tested a sixth one a type S thermocouple which measured -2oC but this thermocouple gives varying (+/- 2oC) results per 'session' (i.e power on
wait a few minutes - measure - power off). The readout is a Sestos temperature controller for a Kanthal furnace.
[img src=thermotest2.jpg
[img src=thermotest2.jpg
[Edited on 2010-12-4 by metalresearcher]The WiZard is In - 4-12-2010 at 07:58
Here I checked five temperature measuring devices with melting snow.
The best is that is converts to slush by adding some tap water.
Mercury thermometers for scientific use are generally of two
types — those designed/calibrated for full immersion or
partial immersion (value on the stem). A decent thermometer
also has a stated +/- temp value.
Some years ago the Amateur Scientist in Scientific American
had plans on building a thermometer accurate to one-hundredth
of a degree.
This all be reminding me of an old saying —
A man who two watches will never know the correct time.
est2.jpg
est2.jpg