How to connect thermocoupler K type to microcontroller?

Hi! I have a thermocoupler K-type. I want to connect it to ADC input of a microcontroller, so I can measure temperature. Could someone post a schematics how to do it??? I`ll measure room temperature with 1 degree tolerance. Thanks!

Re: How to connect thermocoupler K type to microcontroller??

I`ll measure room temperature with 1 degree tolerance.

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It's not an appropriate sensor for room temperature. Better to use an alternate sensor, such as an RTD.
Better still, just use a device like SE95D or other IC temp sensor.
If you meant that you will compare with room temperature, then maybe just use MAX31855K, it is
simpler.

Re: How to connect thermocoupler K type to microcontroller??

My fault, sorry! It`s not room temeperature, it`s water with room temperature. Because of this I`m using this termocoupler. It`s easier to stabilize it in the water, because it has carving.

Re: How to connect thermocoupler K type to microcontroller??

Hi,

To measure room temperature TC is not suitable, RTD and Integrated silicon (temperature sensing IC) are better. TC are better for localized, fast fluctuating, high accurate and broad range temperature measurements.
Following is a good introduction; ww1.microchip.com/downloads/en/appnotes/00684a.pdf

But still you want to play with TC;
You can skip ADC, cold-junction compensation and linearization if you select TC digitizing ICs like MAX31855, MAX6675(same accuracy as MAX31855, but 5V supply and low cost)
**broken link removed**

Also AD8495 or AD595 do cold-junction compensation and amplifying then output a voltage proportional to temperature.
https://www.analog.com/en/mems-sensors/digital-temperature-sensors/ad8495/products/product.html
https://www.analog.com/en/mems-sensors/digital-temperature-sensors/ad595/products/product.html

If you are going to do signal conditioning, cold-junction compensation, ADC and linearization,
INA128 and INA129 are good choice as instrumentation amplifiers and ADS1146 or ADS1246 can be used as ADC. Read datasheet of them.
https://www.ti.com/solution/isolated_thermocouple
https://www.ti.com/general/docs/litabsmultiplefilelist.tsp?literatureNumber=sbaa180

Re: How to connect thermocoupler K type to microcontroller??

If I have understood you right this must be my chart. I have aditional problems to solve, so I want to use TC and 15V Vcc. Is it correct or I have make so changes???

Re: How to connect thermocoupler K type to microcontroller??

I think that is better first to search EDABoard forum using search field in upper right corner of screen, there is other threads with that topic.

Re: How to connect thermocoupler K type to microcontroller??

Hi, DineshSl

As per you advice i had tried 'K' type thermocouple with PIC16F877A to display temperature on LCD/7-segment display.

But as the datasheet says we need to follow a "NIST" table to minimize the non-linearity problem.
(that table shows -270 to 1372 C corrosponding mv ranges)

But i think it very difficuilt to save those kind look table concept even that much longer size table it's also not saved in code.

(One +ve response of hall story is that a simulation result of AD8495 gives me exact matched corrosponding mV o/p as described in datasheet of AD8495 )
Does there any other way to do it??

Here i had attached a simulation project of Proteous8.

Kindly go through it and provide me necessary solution.

Thanking you in advance.

Hardik Patel