Brattoli M., Cangialosi F., Fornaro A., Giannuzzi M., 2026, Operational Protocol and Proposed Acceptance Values for Quality Assurance in Instrumental Odour Monitoring Systems (IOMS) Under UNI 11761:2023, Chemical Engineering Transactions, 127, 91-96.
The metrological robustness and long-term stability of Instrumental Odour Monitoring Systems (IOMS) are critical for their reliable application in environmental monitoring and regulatory frameworks. In Italy, the application of IOMS is addressed by the national guidance (Director Decree No. 309/2023) and by the technical standard UNI 11761:2023, which defines verification procedures but does not provide quantitative acceptance values for the resulting performance indicators. This study presents an operational quality assurance protocol applied to IOMS installations, developed to support practical field implementation of the verification procedures defined by the technical standard. The protocol encompasses validation of the instrumental odour metric (quality assurance level 2) and periodic performance monitoring (quality assurance level 3). Level 2 verification is based on statistical comparison between IOMS outputs and dynamic olfactometry measurements, while Level 3 verification assesses instrumental stability and accuracy over time using span gases at certified concentrations. Based upon long-term operational datasets and experience gained from managing multiple installations subject to regulatory requirements, this paper proposes a methodological approach for IOMS management and introduces quantitative acceptance values and decision thresholds to support system verification and corrective actions when necessary.
