From: Spehro Pefhany
Subject: Re: Temperature Measurement Stability
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Date: Thu, 14 Nov 2002 02:02:16 GMT
NNTP-Posting-Date: Wed, 13 Nov 2002 21:02:16 EST
On Wed, 13 Nov 2002 19:19:44 -0500, the renowned "Raymond E. Rogers"
>I have a manager problem and would like a good Temperature Measurement
>reference to beat somebody over the head.
>We need to build an instrument that has .15 degC stability across
>instruments and over time; this is at a single fixed temperature 37
>degC. I am trying for the temperature measuring part to be .03 degC
>I am trying to convince somebody that we need to recalibrate annually or
>biannually; or be convinced different. I would like a reference that
>has explicit authoritative statements and hopefully data, concerning the
>long term stability of:
Yes. Particularly if they won't be exposed to temperatures outside
the normal ambient range, otherwise they may show some small
>Glass Encapsulated "Super" thermistors
Maybe, if treated well (as above).
>Semiconductor temperature sensors, like those used in Dallas
Maybe, but I don't trust them.
What's wrong with an accurate mercury-in-glass thermometer? Not
expensive, and it sounds like you have a very controlled situation, so
the long response time and immersion depth requirement shouldn't
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