Initial Calibration Interval means an interval that we used initially as per the decision of the expert, this should not be the final calibration frequency to be used, this is just our starting point. Since we do not have yet data to justify this interval (in most cases for start-ups), it is known as ‘Engineering Intuition’.
I will quote this statement from ILAC G24, It states:
“The so-called “engineering intuition” which fixed the initial calibration intervals, and a system which maintains fixed intervals without review, are not considered as being sufficiently reliable and are therefore not recommended. “
The decision on where to base the initial calibration interval depends solely on you as the user. These could be based on below criteria:
1. Manufacturer Requirements – recommended by manufacturer
2. On the frequency of use – the more it is used, the shorter the calibration interval
3. Required by the regulatory bodies (example: required by the government)
4. Past experience of the user with the same type of instrument
6. Based on the criticality of use. – more critical instruments have higher accuracy or very strict tolerance, therefore shorter calibration interval
7. Customer Requirements
8. Conditions of the environment where it is being used.
9. Published Documents
Initial calibration intervals in some cases could become the ‘fixed/final calibration interval’, considering that we already have evidence to justify why we decide on this calibration interval for a specific instrument. I will share 1 method to be used for justification.. Just continue reading.
Remember that the above choices are the basis for an initial interval, our job is not finished here yet. The next move is to determine or to establish the final or ‘fixed Interval of calibration’ using a specific method or procedure. And this is where the method that I will present here will be used.