Index of content:
Volume 82, Issue 2, February 2011
Comment on “A versatile thermoelectric temperature controller with 10 mK reproducibility and 100 mK absolute accuracy” [Rev. Sci. Instrum.80, 126107 (2009)]82(2011); http://dx.doi.org/10.1063/1.3534845View Description Hide Description
Libbrecht and Libbrecht recently described a thermoelectric temperature controller for which they claimed an absolute accuracy of 100 mK. They did not specify the heat-dissipation coefficient for their thermistor temperature sensor—which would dissipate more power than is usual in such circuits— nor make any allowance for self-heating in the thermistor. Self-heating can be expected to have introduced more than 100 mK of absolute error in their circuit.
Response to “Comment on ‘A versatile thermoelectric temperature controller with 10 mK reproducibility and 100 mK absolute accuracy”’ [Rev. Sci. Instrum.80, 126107 (2009)]82(2011); http://dx.doi.org/10.1063/1.3534860View Description Hide Description
The preceding comment by Sloman points out that the absolute accuracy of a temperature controller may be compromised by thermistor self-heating. We measured the self-heating of the thermistor used in our temperature controller, verifying a systematic error of nearly 200 mK. However, this error is reduced by over an order of magnitude with a slight change in our original circuit design. With this change, our controller does achieve an absolute temperature accuracy of 100 mK, limited mainly by the stated absolute accuracy of the thermistor used in the circuit.