Red, in this case, calibration of scales is a wise business decision. Where counts are important and relevant to a particular process, be it filling shop orders, verifying counts at R/I, or at shipping, count is important.
As one of the contributors added to the thread, periodic checks of a scales accuracy can be done by using a known standard or set of standards depending on the amount of items being measured.
As an internl QMS auditor years ago, our team was called on to perform the annual inventory accuracy verification audit. We always used calibrated scales.
Bob