Temperature Sensor

Hello

There are a lot of temperature Sensor that can measure high temperature but I do need one that can measure low temperate at around -70 Celsius. (It should be accurate between +30 and -70 Celsius) Does someone know one?

Thx Geko

Most (if not all) electronic detectors don't work that low. Your best bet would be a thermocouple.

Specifically a type T thermocouple; the common type K doesn’t typically go below 0C.

There are probably thermistors that go that low, but I’m not too familiar with them.

In either case you’ll be left with implementing some signal conditioning and amplification. A thermocouple will need a reference temperature junction, and amplifier, and some math to get an absolute temperature out of it.

As Grumpy_Mike says, most integrated devices don’t go that low. I happen to have on my desk an AD22100, which only goes to -50C, and that’s the lowest integrated device I’ve seen.

-j

Thermocouple Type K are available in the -200C to +1350C range. Sensitivity is approximately 41 uV/C.

hmm Ok thx a lot... I got the DS18B20 and this one goes to -55C..

I have to checkout those Thermocouples...

Thx Geko

If -55 deg is enough for you, you'll be a lot happier with the 1-Wire chip... a joy to use. And you can have mulitple sensors easily, sometimes a consideration. And no calibrating of amplifers, etc, to contend with.

1-Wire fan club at...

http://www.arunet.co.uk/tkboyd/e1didx.htm

-55 deg is more or less enough -80 would be much better but I haven't found a solution for the arduino yet to measure that low temperature... Do you have any ideas?

Geko