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Calibration of thermometers

Discussion in 'ISO 17025 - Calibration and Test Laboratories' started by Sergio Rufini, Aug 9, 2017.

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  1. Sergio Rufini

    Sergio Rufini New Member

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    Hello,

    I have a doubt about the calibration of the single thermometers.

    In our labs we have a measurement system for test composed of:

    Agilent Datalogger 34970A
    Agilent Multiplexer 34901A
    4wires Platinum Thermometers PT1000 (accuracy Class B IEC 60751)


    According to Agilent Manual the Datalogger and Multiplexer shall be calibrated once a year.

    But what about the thermometers? They have an accuracy that is measured from the manufacturer, but does this accuracy expires?
    Is there a standard that explain what device have to be calibrated and how?
    A system level calibration is not a real option for us, since the thermometer are usually changed and substituted for every test.

    Thanks

    Sergio
     
    Sergio Rufini, Aug 9, 2017
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  2. Andy Nichols

    Andy Nichols Moderator Staff Member

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    Manufacturers often publish this. It's a guess. They don't know and can't tell how often the device is used so it's their fall-back position. In reality, you should build a history of "as found" conditions for calibration to help define when the thing should be recalled - based on use.

    You might find something here: http://www.gidep.org/
     
    Andy Nichols, Aug 9, 2017
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    Jennifer Kirley likes this.
  3. Zaccai

    Zaccai New Member

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    I have a follow-up question regarding oven dataloggers; Is there a standard operating procedure / protocol to issue a calibration certificate?

    To the best of my knowledge, it is sufficient to calibrate a datalogger using a certified (traceable ofcourse) oven and a certified thermometer with probes. Is this information correct?
     
    Zaccai, Jan 21, 2018
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  4. Jennifer Kirley

    Jennifer Kirley Moderator Staff Member

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    When issuing a calibration certificate, do you mean simply a record of having done the calibration?

    Certificates that I have seen also include the test method used, the name of the technician, and the actual results along with tolerance requirements (usually an additional figure for amount of error), date and results.

    There is no set protocol that I know of. Indeed I have seen enough variation to make reading the certificates challenging; sometimes important information is not included by calibration service providers for my clients.
     
    Jennifer Kirley, Jan 21, 2018
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  5. Zaccai

    Zaccai New Member

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    Yes, i meant a record of calibration along with all the appropriate information (test method, name, result deviation, date, duration, result, technician), in order to issue an "in-house" calibration certificate which would serve as a complete recording that the device has been calibrated and is traceable to the national metrology institute standard and the SI.

    I couldn't find of any set protocol but i though it would be better to ask about it. Thank you for your feedback!
     
    Zaccai, Jan 21, 2018
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  6. Anthony Salim

    Anthony Salim New Member

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    Have you checked ISO 17025: 2017 - 7.8.4 - Specific Requirements for Calibration Certificate?
    If you have, I think just follow this, should be fine. This is a standard report for a calibration laboratory, so, if use for internal only. I think it should be sufficient. CMIIW
     
    Anthony Salim, Mar 15, 2018
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