Quick thermocouple question.

[neddie]

If I have a k-type thermocouple , what would it's open cct voltage be at say 25 dec C.
It's characteristics as far as I can remember give a v/dec c of about 40uV / dec C give or take.
At 0 degC it won't be zero output voltage surely?
Cheers
Neddie

 

[jpsganesh]

Type K Thermoelectric Voltage
Type K has an exponentially increasing voltage the differences in voltages become easier to measure and more accurate at higher temperatures. At very cold temperatures minus 260° C to minus 250° C type K thermocouple voltages differ only one or two thousandths of a millivolt for every degree Celsius. At extremely high temperatures around 1,350°C voltage differs about 3.3 hundredths of a millivolt per degree Celsius.



Ref:
https://www.thermometricscorp.com/thertypk.html

- - - Updated - - -

http://www.pyromation.com/downloads/data/emfk_c.pdf

http://www.omega.com/temperature/Z/pdf/z218-220.pdf

 

[Dreso12]

If you want linear response from a K-type thermocouple and at a mesurable level with a standard ADC you can try the AD8495 from Analog Devices. It will save you quite a lot of time in signal conditionning.

 

[neddie]

Got me a MAX31855 , problem solved :0)