Hi NG,
for a surface measurement application I need a thermistor (NTC) with a fast response time of max. 200ms in liquids. Where can I buy such things, any recommendations?
Thanks! ~Christian
- posted
15 years ago
fast response thermistor
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- posted
15 years ago
Thermistors are generally poorly suited for surface temperature measurement applications.
Here's one that claims to meet your stated requirements:
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(although the obvious errors on the page lead one to wonder if it really does..)
Best regards, Spehro Pefhany
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- posted
15 years ago
Christian Holzapfel wrote in news:c2f14345-a890-4978- snipped-for-privacy@13g2000yql.googlegroups.com:
Maybe a small Pt100 sensor, the bare unencapsulated kind? You'd need to put come kind of coating to seal the wires but the rest is already sealed with a high temperature glaze, and the response speed and low cost of the smallest types might make them ideal.
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- posted
15 years ago
Lostgallifreyan schrieb:
Do you have any links, company names e.g. to such small and fast sensors? A Pt100 would be suitable as well, but all of them I found on the internet while googlin' seem to be slower than the NTCs available.
In addition to the fast response time (
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15 years ago
Christian Holzapfel wrote in news:gh6vp1$ssr$ snipped-for-privacy@inlux3.rz.uni-kiel.de:
Nope, I looked at RS, but theyr range shrunk, it seems. Thing was about 5 mm long, 2 mm wide, and it should be fast as it was thin and built on a thermally conductive ceramic. All moot though, if you also need strong electrical isolation try what Phil said, sense radiation not conduction. It's cheap enough, by the look of some initial Google results.
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- posted
15 years ago
Spehro Pefhany schrieb: > Here's one that claims to meet your stated requirements:
Sphero, thanks for your reply. I already found betatherm.com by myself, but unfortunately they did not reply to any of my requests. Since I live in Germany and this is of semi-private interest, callin' the US would be too much. They have a nice NTC with a TC of 30 (!) ms in liquids, which would be ideal. Maybe I can find a local distributor...
~Christian
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- posted
15 years ago
So the sensor is going to be permanately attach with glue ? No liquids ? Most are insulating. The trouble is spacing. I have used diamond dust to help out as a spacer, You can apply a thin epoxy coat first, before the final attachment, but I don't know the response.
greg
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- posted
15 years ago
If all else fails consider AC excitation and transformer coupling. Or run the whole circuit isolated (that's what we do on ECG systems).
-- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.