Help PT100 sensor

[Algerian]

Hello,
I want to get temperature readings with pt100 sensor, does any one have a circuit to connect it to pic16f877, thanks in advance

 

[j.p.bill]

If that is a platinum RTD, you will need to send a currrent through it from a controlles source. Using a high-quality amplifier, amplify the voltage on the RTD up to a level compatible with the A to D converter in the PIC. After conversion, apply the values against a look-up table to linearize the signal.

One observation, though - an RTD is a very expensive and precise measurement device. Reading it with an 8 or 10 bit A to D is a bit like measuring dimensions in ells and spans. The units are just too coarse to give good results.

 

[Algerian]

If that is a platinum RTD, you will need to send a currrent through it from a controlles source. Using a high-quality amplifier, amplify the voltage on the RTD up to a level compatible with the A to D converter in the PIC. After conversion, apply the values against a look-up table to linearize the signal.

One observation, though - an RTD is a very expensive and precise measurement device. Reading it with an 8 or 10 bit A to D is a bit like measuring dimensions in ells and spans. The units are just too coarse to give good results.

Thank you very much for your reply, but please, if you have a reference of the high quality amplifier, or if you have the circuit with refernces and values will be very helpfull. Thanks again.

 

[RadioRon]

If you are in a hurry, just buy one of these:
**broken link removed**

If you want to build from scratch, Maxim has some chips specific to this application:

**broken link removed**

and here is a useful application note with IC references:
https://www.electro-tech-online.com/custompdfs/2007/06/AN3450.pdf