Hi,
Darn, Bob beat me to it! I was going to suggest the AD590 and a suitable
ADC. The ceramic part is relatively small.
https://www.digikey.com/product-detail/en/analog-devices-inc/AD590JF/AD590JF-ND/611802
It's not as small as a thermistor, but not overly large. They have other
packages as well.
The smallest device is probably still a TC (40 gauge TC wire is small!)
But honestly getting down below .1 Deg C can be hard to do. (If the
icepoint reference doesn't have the resolution you'll get jumps in the
curve as ambient changes.)
For thermistors, at least a ways back GE Thermometrics sold glass
packaged parts with calibration coefficients. They weren't really cheap,
but were small and accurate enough.
Honestly, if it were an experimental setup and not production I'd just
grab some glass packaged parts from digikey (looks like a lot of options
around a few $ ea.) . Bias it with a resistor from a fixed supply, then
run a three point calibration (Icepoint, boiling point, and somewhere in
between) and generate calibration coefficients. Pair that with a
inexpensive-ish 24bit ADC, and you'll have all the resolution you want.
You should get sub .05 deg accuracy, at least short term. Skip the
calibration and just use the published B value, and you'll still have
the resolution.
Let us know what you settle on.
Dan
On 9/26/2020 9:45 PM, [email protected] wrote:
Date: Sat, 26 Sep 2020 11:23:45 -0400
From: Bob kb8tq<[email protected]>
To: Discussion of precise time and frequency measurement
<[email protected]>
Subject: Re: [time-nuts] What do people use for measuring temperature?
Message-ID:<[email protected]>
Content-Type: text/plain; charset=utf-8
Hi
One interesting ?oops? using RTD?s:
They are close cousins of strain gauges. Some RTD designs are*very* close.
Mount them to this or that and they may tell you more about the stress / strain
in the mount than about the temperature.
You do*not* want to know how many (hundred) temperature test chamber sensors
that particular goof messed up ?? 4 sensors per chamber, 8 in a pod, three pods
in the factory here, four pods in the factory down south, Two partials in
engineering,
two partials in QA ?.
The answer ultimately was to tear out all the RTD?s and replace them with
carefully
tested (= sorted) AD590?s.
Bob
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