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Problem deal with accuracy of thermocouple

  1. Apr 21, 2011 #1
    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..
  2. jcsd
  3. Apr 21, 2011 #2
    Just go and see what you get with ice and boiling water. That is a great idea to start with.
  4. Apr 22, 2011 #3
    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 ?
  5. Apr 22, 2011 #4
    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.
  6. Apr 22, 2011 #5
    Unless you're at altitude.
  7. Apr 23, 2011 #6
    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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