ISO 9169:2006

Overview

ISO 9169:2006 - Air quality: Definition and determination of performance characteristics of an automatic measuring system defines terms and specifies methods to determine the performance characteristics of identified automatic air quality measuring systems (AMS). The standard treats an AMS as a “black box” operated according to specified procedures and covers tests performed under stable laboratory conditions and selected field conditions. ISO 9169:2006 applies when the measuring system provides results in physical units, has documented operating and calibration procedures, and when suitable reference materials with accepted values and known uncertainty are available.

Key topics and requirements

• Scope and prerequisites
  • Applies to automatic measuring systems (continuous or discontinuous) that output the measurand in physical units and have documented operating procedures and terms of reference.
  • The client specifies the test program, test conditions and the number of systems to test.
• Definitions and terminology
  • Clear definitions for measurand, reference material, calibrated state, averaging time (laboratory vs field), primary result, interferent and influence quantity.
• Performance characteristics (laboratory and field)
  • Response time (rise, fall, lag) and minimum averaging time
  • Repeatability, lack of fit (linearity), limit of detection
  • Drift (short-term and field drift) and availability
  • Sensitivity to interferent influence quantities and external influence quantities
  • Standard deviation of paired measurements for field comparisons
• Test methods and reporting
  • Tests under steady laboratory conditions to control influences and reduce drift effects.
  • Field tests where relevant (e.g., availability, paired measurement variability).
  • Requirements for the testing laboratory and the structure of the test report.

Applications and who uses this standard

• Environmental testing laboratories validating or certifying automatic air quality monitoring systems.
• Manufacturers of AMS seeking standardized evaluation of metrological performance.
• Air quality networks, regulatory bodies and emissions monitoring agencies that require documented performance characteristics for instruments used in ambient air or emission monitoring.
• Consultants and test program clients who define terms of reference for acceptance testing and calibration validation.

Related standards

• ISO 11095 (calibration concepts referenced)
• ISO 11843 (detection capability concepts)
• GUM (Guide to the Expression of Uncertainty in Measurement) - expanded uncertainty concepts referenced

Keywords: ISO 9169, air quality, automatic measuring system, performance characteristics, laboratory testing, field conditions, calibration, reference material, response time, repeatability, drift.