A Guide or Standard for Calibration Interval (Frequency)

[mkabiel]

i want to extend the calibration interval for some instruments, so i need a method , guide or sstandard to be documented?

 

[Ajit Basrur]

Re: Need a guide or standard for calibration interval

i want to extend the calibration interval for some instruments, so i need a method , guide or sstandard to be documented?

Would these help ?

https://www.ilac.org/documents/ILAC_G24_2007.pdf

http://tf.nist.gov/service/pdf/calibrations.pdf

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[Charles Wathen]

i want to extend the calibration interval for some instruments, so i need a method , guide or sstandard to be documented?

You can start with RP-1 NCSL Recommended Practice ? Establishment and Adjustment of Calibration Intervals January 1996

but without reading the entire document, it's up to you to determine when to extend a calibration interval on an instrument. In our policy here, we have adopted a review of previous calibration history. For example, if I have an instrument that is calibrated every 12 months, and the last 3 calibrations show no OOT's, then there is a very low risk that it will be found OOT when calibrated.

If you group your instruments in to families (i.e. calipers for example), you can reveiw all of your calipers for OOT's and then determine your reliability for the family (number in tolerance divided by the number of calibrations). We go through this process here, but sometimes we may have situations were it may fail our test and be below our target reliability rate of 95% or greater. This then goes back to the owner of the process or instrument: we document the potential risk, but the owner of the process or instrument can over-ride us with a quality approval.