Temperature Measurement

[Simon]

hm I'm looking for something cheap and easily available

[migsantiago]

Another great recommendation a friend gave me... MCP9700 from Microchip. It's a TO92 chip with a +/-2°C precision and it costs half the price an LM35.

http://ww1.microchip.com/downloads/en/DeviceDoc/21942e.pdf

[Simon]

yea I spotted that today on Farnell looks interesting at 30 pence

[allanw]

Solving the diode equation shows that the voltage is in theory linear as a function of absolute temperature, if the current through the diode is constant, Vf=ln(I/Is+1)*nkT/q.

Yes, but I_s itself is dependent on temperature.