ECN Electrical Forum
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What sort of materials are PTC and NTC Thermistors made from?.
Also is their Temperature/Resistance response a linear thing, or does the resistance rise/fall at a logarithmic rate?
You help would be most appreciated.

Thermistors are made of various semiconductor materials. They are very much _not_ linear.

Take a look at these guys for datasheets, including resistance versus temperature tables.
http://www.vishay.com/thermistors/ptc/
http://www.vishay.com/thermistors/ntc/

-Jon

Definitely NOT linear, nor would we want them to be in many applications.

The exact curve isn't necessarily purely logarithmic either. Different types can be formulated to have varying characteristics to suit the intended application.

Thanks for the info, guys.
I was just wondering about these devices, having never had much to do with them in the past.
And I most certainly didn't know that they were made of semi-conductor materials.