Problem deal with accuracy of thermocouple

AI Thread Summary
To ensure the accuracy of a thermocouple, it's recommended to test it in ice and boiling water to confirm it reads 0°C and 100°C, respectively. If the readings differ, such as a higher value for ice, adjustments may be necessary, like subtracting the error from future measurements. For applications requiring greater precision than ±1.1°C, consider using a thermistor or RTD instead. It's important to reference the thermocouple's specifications for accuracy limits and to document these in any presentations or charts. Additionally, ensure the cold junction reference is accurate, and use pure water for the ice test to avoid errors.
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How i am going to confirm or make sure the accurate of thermocouple before i use it for measurement in experiment?
Is it ok if ...
I put it in ice in order to get 0 Celsius and put in boiling water to get 100 Celsius?
In the idea case, i should get 0 and 100 Celsius from thermometer..
but what i should do if i got slightly different ?
I don't know how to present about the error if i use it for real experiment...i need help on it...please..
 
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Just go and see what you get with ice and boiling water. That is a great idea to start with.
 
Dr Lots-o'watts said:
Just go and see what you get with ice and boiling water. That is a great idea to start with.

I did a try already..i got a slightly higher for ice. 1.1 Celsius..
If like this..
this mean i have to minus 1.1 Celsius for all value by using that device ?
 
If you need something more accurate than +/- 1.1 deg. C, use a thermistor or RTD. Don't use your TC's for that application. As far as results go, you should have some specs on that specific thermocouple that say what the accuracy of your measurements are. For example, +/- 1.5 deg over the range of 40 deg C - 375 deg C. Consider checking out OMEGA's website for typical errors for a thermocouple class.

If you need to present the temperature in a chart, simply plot the recorded values and add a foot note that shows the accuracy limitations. However, if you are taking the temperature measurements and using them to plot something as a function of temperature you probably need to adjust the accuracy accordingly. Google error propagation.
 
Dr Lots-o'watts said:
Just go and see what you get with ice and boiling water. That is a great idea to start with.
Unless you're at altitude.
 
That should be a mixture of ice and water to get 0, but make sure that you are using pure water, your other source of trouble is your cold junction reference how accurate is that?
 
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