Linearisation of thermocouples, RTD using MCP3426

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#1
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I am trying to develop a temperature indicator using ATmega16 uC & MCP3426 16-bit delta-sigma ADC.

The input to this indicator will be either be a thermocouple or RTD.

So can anyone suggest me a simple algorithm in C for linearising the thermocouples or RTD.  

Gaurav Gawade

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This subject has been done to death. Surely a quick Google will give you the answers you seek. Add Arduino to the search to make it a bit more relevant.

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Though this subject has been done to death, I still need some help as I'm not getting an idea of how to implement it.

Gaurav Gawade

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RTD is inherently quite linear. Thermocouple much less so. But, with both you need much more than an ADC. With a thermocouple, you need something that is effectively the "cold junction". With RTD, you need some very stable resistors and very careful wiring. You could do a LOT worse than one the temperature sensor interface ICs made by (I think) Linear Tech, Analog Devices, or Maxim. These take care of linearization, cold junction "issues", and a lot more.

 

For thermistors, THE equation is known as "Hart and Steinhart Equation".

 

Jim

 

Until Black Lives Matter, we do not have "All Lives Matter"!

 

 

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But how to write the algorithm for linearisation of thermocouples & RTD's using C?

Please help me in writing this algorithm as I'm not getting an idea of how to write it.

Gaurav Gawade

Last Edited: Tue. Jul 25, 2017 - 03:26 AM
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Less than 10 seconds:

https://learn.adafruit.com/calib...

I Googles Arduino thermocouple linearisation

You do realise that Arduino is C/C++?

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Thanks.

Gaurav Gawade