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From: skip@rafos.UUCP (Skip Carter)
Newsgroups: sci.electronics,sci.physics
Subject: Re: Anyone know the general equation for a thermistor?
Summary: Thermistors & chips
Message-ID: <424@rafos.UUCP>
Date: 31 May 90 16:40:36 GMT
Article-I.D.: rafos.424
References: <90137.132911F0O@psuvm.psu.edu> <1990May19.003327.12503@agate.berkeley.edu>
Followup-To: sci.physics
Organization: School of Oceanography, Univ of RI, Narragansett, RI
Lines: 24

In article <1990May19.003327.12503@agate.berkeley.edu>, aephraim@typhoon.Berkeley.EDU (Aephraim M. Steinberg) writes:
> ......  However, there are chips (AD590, perhaps?) put
> out by Analog Devices, which give a current they claim to be absolutely
> proportional to the temperature in Kelvins, accurate to 2 or 5%, depending
> on how much you pay.  Also depending on how accurate your 5V supply is,
> ....
> If anyone knows any more about these chips or relatives of theirs, I'd be
> interested to hear about it.
> 

	We have looked at these chips for in situ temperature measurements
in the deep ocean.  They don't seem to be as precise or as stable as a good
thermistor, so we went back to using thermistors.  (Some labs I know of buy
thermistors a year in advance and keep them on a shelf for a year -- they
claim vastly improved stability when they do this).
	By STABILITY, I mean that I always get the same measurement for the
same temperature (Its far more important for ocean measurements to get 17.15
everytime I measure 17.3 degree water, than it is to get closer to 17.3)

-- 
Skip Carter			UUCP:	uunet!rafos!skip
School of Oceanography	    INTERNET:   skip@rafos.gso.uri.edu
University of Rhode Island     Phone:   401-792-6519
Narragansett, RI 02882