What is it about?
Libbrecht and Libbrecht ran their sensor too hot, which made nonsense of one of their performance claims,as well as being inconsistent with previous practice.
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Why is it important?
There was nothing unique in the comment, it just reiterated previous practice with a bit of backing detail. The backing detail reflected an experience I'd had with thermistors around 2002, where an automated calibration rig had pushed the dissipation in a particular thermistor high enough to make its resistance visibly unstable (though it didn't move around much). I took the chance to point out that negative resistance devices can form "hot channels" if you dissipate enough power in them - I've seen it done with carbon film resistors - and that this might be why early publication on using thermistors as precise temperature sensors had emphasised that you ought to keep the power dissipation low if you wanted good stability.
Perspectives
Everybody gets peeved when their work is cited by people who hadn't actually read the original work as carefully as they should, but Libbrecht and Libbrecht had thrown in an ill-founded claim about absolute accuracy which made it easy to make the point. Power dissipation in precision thermistor sensors does need to be taken seriously, and the point has always been emphasised in the relevant literature. I was happy to be able to hammer the point home again, and throw in a bit of extra evidence which wouldn't have been worth publishing on its own.
Dr. Bill Sloman
IEEE
Read the Original
This page is a summary of: Comment on “A versatile thermoelectric temperature controller with 10 mK reproducibility and 100 mK absolute accuracy” [Rev. Sci. Instrum. 80, 126107 (2009)], Review of Scientific Instruments, February 2011, American Institute of Physics,
DOI: 10.1063/1.3534845.
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