Expression of expanded uncertainty in accreditation scope regarding ILAC P14
We discuss the scope of accreditation presentation in certificates and annexes issued by NABs for calibration laboratories (accredited in accordance with ISO/IEC 17025 [1]) in accordance with ILAC P14:2020 [2], with specific requirements stated in clause 4.3 for expression of measurement uncertainty (expanded uncertainty) regarding the unit. Due to the close link between accreditation, metrology, and standardization, we consult BIPM documents [3] and discuss the practice in metrological institutes when it comes to expressions of expanded uncertainty in order to give another view and arguments on ILAC P14:2020 requirement for expanded uncertainty to be expressed only in terms of measurand's unit. We present our case for the quantity of temperature, in addition to some other physical quantities with similar cases as temperature.