Does the method of adjustment matter, or just the final calibration?
- by Steve
A company produces software (and hardware) that is used to both perform automatic adjustments on electronic test equipment as well as perform calibrations of the same equipment. The results of the calibrations are put onto a certificate of calibration that is sent to the customer along with the equipment.
This calibration certificate states various conditions of the calibration, such as what hardware (models/serial numbers) and software (version) was used to perform the calibration, as well as things like environmental conditions, etc.
Making the assumption that the software used to produce the data (and listed on the calibration certificate) used on the certificate of calibration must have gone through a "test/release" process and must be considered "released" software - does this also mean that the software used for adjustment must also be released?
I believe that the method (software/environmental conditions/etc) used or present during adjustment doesn't matter, all that really matters is the end result of the calibration, the conditions present during the calibration, and whether or not the equipment was within the specifications.
The real question I'm hoping to get answered: Is there a reputable source (e.g. NIST or somewhere similar) that addresses this question? (I have searched...)
The thinking is that during high volume production runs, the "unreleased" system can be used to perform adjustments, as long as a released system is used to perform the calibrations, since the time required to perform the adjustments is much longer than the calibration. This unreleased system will eventually become released for use, but currently is not.
Also, please not that there is a distinction between "adjustment" and "calibration". The definition from BIPM International vocabulary of metrology, 2.39:
Operation that, under specified conditions, in a first step,
establishes a relation between the quantity values with measurement
uncertainties provided by measurement standards and corresponding
indications with associated measurement uncertainties (of the
calibrated instrument or secondary standard) and, in a second step,
uses this information to establish a relation for obtaining a
measurement result from an indication.
Followed by NOTE 2 (emphasis in original text):
Calibration should not be confused with adjustment of a measuring
system, often mistakenly called "self-calibration", nor with
verification of calibration
As a side note, I'm not sure why this got down voted. It's regarding software and it's use before and after release for use. I believe there is a best practice that can be applied and this is (hopefully) not primarily opinion based.
