Re: Converting a NTC voltage into temperature in Celcius

On 8/04/2025 7:54 pm, Jean-Pierre Coulon wrote:

The resistance vs temperature relation is well known. But we are using one with an industrial controller that sends 100 uA into it and provides the corresponding voltage.
 Are there any cheap converters on the market, to convert this voltage into a nice linear voltage vs temperature relation ? Then there there are many voltage-to-display converters.

I don't know of any. The Steinhart-Hart relationship has been around since 1968
https://en.wikipedia.org/wiki/Steinhart%E2%80%93Hart_equation
but if you need more accuracy you need more parameters.
Getting the parameters in the first place needs work, so the "cheap converter" wouldn't be cheap to use.
The look-up table approach with linear interpolation between a limited number of points is easier, and thermistor suppliers do published tables of resistance versus temperature, but the user would have to get the tables into the "cheap converter" which takes skilled labour, which isn't cheap.
--
Bill Sloman, Sydney