Firstly, I would like to apologize for the lack of prompt response on my side due to the fact that I was on holiday. Thanks for every post that the thread has received. I have now managed to convince my colleague that he indeed misinterpreted the standard in this regard. The standard states that “equipment shall be calibrated or verified…… against measurement standards traceable to international or national measurement standards: (AND ONLY) where no such standard exist, the basis used for such calibration or verification shall be recorded.” Therefore, checking or verification equipment against unknown traceable international or national measurement standard is unacceptable unless where no such standard exists.