Traceability of Measurement Result on an Approved Instrument
To obtain an admission from the CFS scientist that the traceability of a measurement result on an approved instrument or a truck weigh scale is through the calibration of the instrument at the factory or a proper recent re-calibration by the manufacturer or factory authorized service centre. At the time of calibration a calibration curve is created to establish a relationship between the electrical signal coming off the detector in the AI or the weigh scale and the digital indication. That isn't done using controls at time of use.
To clarify that calibration of a gas chromatogaphy instrument used for blood, urine, serum analysis is done quite differently at time of use. A calibration curve on a gas chromatograph is created electronically at time of use.
Traceability of a measurement result on an AI is therefore through the manufacturer's Certificate of Calibration or re-calibration certificate. The Certificate, reference standards, and methodology at the time of calibration or re-calibration are therefore relevant (and essential) to reliability of the measurement result.