The sensor will be used to measure snow temperature.
I need an accuracy of 0.1 degree and around -40 , + 20 degree range.
Does anyone know such a sensor ?
Thank you.
Would a DS18B20 do the job, once calibrated?
You are going to have to deal with the issue of the actual physical contact between the snow and the sensor. If the snow is very dry, you will be measuring the air temperature. And if the snow is a bit wet, you will be measuring the water temperature, which is going to be 32F / 0 C almost by definition.
you might want to connect a waterproof version of the DS18B20 sensor to a metal plate that lies in the snow...
Be careful if 18B20 works from -55C to +125 C it is not the case of all other sensors.
Generally, part number with" Z" extension works only from 0C to +70 C ex LM35 DZ.
The extended version -40C +80C is LM35DN, D means DIP or DUAL IN LINE.
Have a look here, it contains some other alternatives than the one which was proposed
http://www.dipmicro.com/store/index.php?act=viewCat&catId=546
I think your need of 0.1 degree accuracy over any reasonable range to be awful ambitious, you are talking big buck laboratory quality instrumentation.
When you say you need an accuracy of .1 do you mean a READOUT to .1 (18.1) or actual ACCURACY to .1?
There is quite a difference and a few hundred to thousands of dollars difference between the two.