Calculating Normalized Error Scores for Multi Facility Calibration Variance Analysis
Calculating normalized error scores isolates facility bias from measurement noise by evaluating raw offsets against combined expanded uncertainties.
Proficiency Testing
Competence Verification
Evaluation of laboratory performance against pre-established criteria by means of interlaboratory comparisons verifies the technical competence of calibration and testing facilities. For ISO/IEC 17025 accredited labs, proficiency testing validates their measurement methods, equipment and staff capabilities. This process requires laboratories to measure a standardized transfer standard and submit their results to an independent organizer.
The program is limited to laboratories that perform standardized measurements with defined uncertainty budgets.
Interlaboratory Comparison
Organizers distribute a stable artifact to the participating laboratories, which must calibrate it using their standard procedures. The results are compared using statistical methods like the En score to determine if the laboratories are performing within their declared uncertainties. Participating in proficiency testing allows a laboratory to identify systematic errors that might go unnoticed during internal audits.
This participation is required to maintain laboratory accreditation.
Performance Assessment
Analyzing the results from many laboratories helps to establish a consensus value for the transfer standard. This value represents the true value against which each laboratory’s performance is measured. If a laboratory’s results diverge from this consensus, it indicates a potential issue with their equipment or training.
The laboratory must then perform a root-cause analysis to resolve the discrepancy.
Quality Assurance
Completing these rounds successfully provides customers with confidence that the laboratory’s measurements are traceable and accurate. This confidence is essential for industries that rely on precise sensor calibrations, such as aerospace and manufacturing. The test results are documented in public registers.