need a temperature sensor with .1 degree accuracy

surjones · 2005-10-13T11:47:08+00:00

I'm pretty new to thermal sensing and such, but I have a friend whowishes me to make/aquire 3 types of temperature sensors, all withgreater than .1 degree celsius accuracy.1) Ambient temperature2) Contact temperature3) Radiation temperature (a "directional" sensor of sorts which detectsIR radiation coming from a source). A further requirement is that ifthis sensor (or array of sensors) can tell me the temperature /amountof radiation in each Thermal IR band within 8.125 to 11.60 Micrometers(total 5 bands within this bandwidth)(This should preferable correspondto a satellite sensor band seperation, as he is doing some urban heatphenomenon research).I've done some experiments with NTC Thermistors before-I did someinterfacing to the PC joystick port. I thought maybe I can use the sameNTC thermistor for the above uses? Is the thermistor meant for "such"sensitive work? (If I uses a better ADC)..and can I modify it in someway to measure the radition temperature as well? (by adding some sortof parabola?!)It would be best if I can get cheap sensor(s) which I can interfacemyself (to the PC), but worst comes I can buy one/seperate standalonedevices which preferable have some sort of computer connectivity andsome memory.Many thanksSuraj

Oct 13, 2005 46 Replies

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The Real Andy 20 years ago

When i was an apprentice so long ago, I remember the company i worked for using one junction of a transistor for doing 0.1degC. Accuracy was actually a lot better, but thats all they could claim becasue of the equipment used for calibration.

I remember that everytime they got a new batch of transistors, i would have to spend days with an old 4wire thermistor and meter to make readings every 0.05degC. Sitting with an ice bath waiting for the ice to melt and trying to zero that meter was a right pain in the arse. Calibrating the standard device was the same, and that had to be done every three months.

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surjones 20 years ago

Oops! It was the price of the vinyl carrying case that I saw! the thermometer is around 180$

Suraj

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DaveM 20 years ago

Wow!!!! For 30 bucks, you'd think it would be gold gilded eelskin

Dave M MasonDG44 at comcast dot net (Just substitute the appropriate characters in the address) Never take a laxative and a sleeping pill at the same time!!

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surjones 20 years ago

I recommended the EW-93210-50 Digi-Sense=AE ThermoLogR Thermistor Thermometer to the friend.

He says measuring ambient is not all that important to him, but contact temperature is, So He'll go in for a probe with the above thermometer. Any recomendations on that? how to get a quick reading with the ideal probe?

For the radiation temperature, there were thermal IR scopes, good ones upwards of 2500 $, but certainly the accuracy was pretty limited, +-2 degree C or so. Then each had a distace to object ratio, an angle of intercept etc.

I asked him to also do a post here, in my attempt to be discreet about the application, I meight have created a little confusion! (specially when I saw some posts about the Satellite sensors...) He is doing research on the "urban heat island phenomenon" and is using ASTOR satellite's thermal sensor imagery (20 Meter to a pixel resolution).

Meanwhile I'm working on a couple of thermistors with look up tables...

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Rich Grise 20 years ago

Is eelskin really all that durable?

Thanks, Rich

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DaveM 20 years ago

Yeah, eelskin is pretty rugged. Years ago when it was very popular, my ex had eelskin purse, cigarette case and wallet set. The cig case and wallet got heavy use, and aside from a bit of discolorization from handling, they never suffered any other damage. None of the sewn seams ripped open, none of the nylon lining came loose, etc. Overall, they were really more rugged than similar leather items that she has owned. But, that's just anecdotal evidence... no scienterrific research involved in my opinion. Cheers!!

Dave M MasonDG44 at comcast dot net (Just substitute the appropriate characters in the address) Never take a laxative and a sleeping pill at the same time!!

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