Abd ul-Rahman Lomax <a...@lomaxdesign.com> wrote: This depends on the probe. However, from other data (such as probe rated > temperature of 150 C.) the probe has an accuracy of +/- 0.4 C. He's greatly > overstated the accuracy, it seems, and that is crucial here. The > *resolution* is 0.1 C., and I think he munges that into +/- 0.05. > > 5- I made my measurements only when the temperature was exactly 100.1 >> Celsius >> > > Plus or minus 0.4 C. >
I have a number of electronic and red-liquid thermometers. I have never heard of one with higher resolution than accuracy, after you calibrate. That makes no sense. If it was plus/minus 0.4 deg C they would set the display to show only half-degrees. (Some do that.) Also, I have not heard of a thermocouple that goes from 0 to 150 deg C but is plus/minus 0.4 deg C. That's 0.3% accuracy. My old Radio Shack one circa 1975 was like that, which is why it displayed only 0.5 deg C increments. I doubt any modern laboratory grade electronic instrument would is that inaccurate. Here are the specs for my Omega HH12B: *Measurement Range:* -200 to 1372°C (-328 to 1999°F) Accuracy (Type K Chromium-Alum): ± (0.1% rdg +1°C) on -60 to 1372°C ± (0.1% rdg +2°C) on -60 to -200°C ± (0.1% rdg +2°F) on -76 to 1999°F ± (0.1% rdg +4°F) on -76 to -328°F http://www.omega.com/ppt/pptsc.asp?ref=HH11B That's 0.1%, for an instrument costing $74. It has a gigantic range, but anyway it is 0.1%. It may be difficult to measure a given temperature to within 0.4 deg C. For example, hot water in a pot is likely to have large thermal gradients. The display will fluctuate a great deal, but the fluctuations real, are not an artifact of the instrument. The instrument itself is good to 0.1 deg C, after calibration. The calibration "OFFSET" screw only adjusts to a fraction of a degree. - Jed
