6.4.8 Fibre counting. 6.4.8.1 Working stage micrometers shall be performance checked at least annually using the traceable stage micrometer. The traceable stage micrometer shall be recalibrated periodically, i.e. every 5 years.
Utter nonsense. The traceable stage micrometer should only need to have it’s calibration checked once, and each working micrometer only needs to be checked once against the traceable micrometer. They should be withdrawn in the scales becomes obscured damaged – analysts will see if this happens when they use them on every job – that is all. Stage micrometer glass scales cannot change dimensions and so the requirement for periodic calibrations must be withdrawn from LAB30.