The Role of Metrology in Ensuring Competence for International Trade Through Proficiency Testing

Abstract

Abstract Metrology's support for international trade through Proficiency Testing (PT) plays a crucial role in ensuring the competence of testing and calibration laboratories. LATU, the National Metrology Institute (NMI) of Uruguay, fulfills its role by maintaining over 130 CMCs (Calibration and Measurement Capabilities) published in the KCDB (Key Comparison Database). Since 2011, LATU, through its Department of Chemical Metrology, has been providing proficiency testing services. It has been accredited according to ISO/IEC 17043 since 2013, initially by UKAS (UK Accreditation Service) and later by OUA (Uruguayan Accreditation Body). As the NMI, LATU is particularly aware of the importance of measurement traceability in proficiency testing programs, regardless of their format. Uruguay is internationally recognized for its role as a major producer and exporter of food products, including beef, dairy, and cereals. Given the importance of these sectors, significant national efforts are directed at maintaining and improving the safety and quality of these products throughout the entire production chain. To support this, LATU organizes various proficiency testing programs aimed at laboratories in diverse fields. LATU offers proficiency testing in three main areas: a) Microbiological testing for laboratories serving food production companies, analytical labs, and certifiers, providing rounds for microbial counts and pathogen detection; b) Physical-chemical analysis for laboratories working with food manufacturers, mills, certifiers, and producers, covering key parameters like moisture, physical defects, protein content, and fat content, which are critical for trade; and c) Secondary calibration laboratories, focusing on mass, temperature, pressure, volume, length, and humidity measurements. In these cases, the assigned values are traceable to SI units through LATU's published CMCs in Physical Metrology. LATU organizes annual, and in some cases more frequent, rounds of proficiency testing with the goal of supporting laboratories in improving their individual and collective performance. Feedback sessions are held within production chains, such as those for rice and soy, to improve result comparability among participants, harmonizing export conditions in some instances and enhancing payment conditions for producers in others. LATU has also collaborated with regulatory bodies to support the certification of food processing and export plants. For secondary calibration laboratories, LATU has provided the necessary evidence for accreditation by OUA, fostering a network of secondary calibration laboratories in Uruguay. Moving forward, LATU aims to continue enhancing the comparability of results from analysis and calibration laboratories, ensuring traceability of reference values to the SI or appropriate international methods or standards for method-dependent parameters.