Hi,
I have the this temperature probe, which I would like to try to get a reading from:-
http://www.polder.com/shop/replacement-parts/replacement-probe-1
Can anyone tell me if I just wire one end up to 5v and the other to analog in? Or do I need a resistor? Also is the polarity critical?
I can experiment with what gives me the best reading but I just want to make sure I'm not going to fry it.
Thanks,
Mark.
That site tells you nothing about the probe.
It could be a thermistor, it could be a thermocouple. A multimeter will
discriminate between these as a thermocouple will exhibit a very low
resistance (an ohm or two at most probably).
A thermistor would have a resistance that varies a lot with temperature
(try dunking probe in boiling water and see if it changes. The resistance
would be more like hundreds or thousands of ohms.
Thermcouples need a precision amplifier so a thermocouple shield or
similar would be needed. Also thermocouples come in several varieties
each with a different response.
Thanks for your help. I will check it with a multimeter tonight.