ISO/TC 146/SC 4 - General aspects

This document specifies terms and definitions that are related to air quality (see 3.1.1.1). These are either general terms or are used in connection with the sampling (see 3.3.3.1) and measurement of gases, vapours (see 3.1.5.8) and airborne particles (see 3.2.2.1) for the determination of air quality. The terms included are those that have been identified as being fundamental because their definition is necessary to avoid ambiguity and ensure consistency of use. An alphabetical index of the terms is provided in Annex A. This document is applicable to all International Standards, ISO Technical Reports, ISO Technical Specifications, and ISO Guides related to air quality.

ISO 11771:2010 specifies a generic method for the determination and the reporting of time-averaged mass emissions from a specific installation or of a family of installations (or common source type), using data collected by measurements, and by establishing: mass emission rates by the simultaneous measurement of concentration and gas flow, using standardized manual or automatic methods, and also the estimation of the uncertainty of the measurements; time-averaged mass emission rates using time series of mass emission rate values, their uncertainty characteristics, and also the determination of the expanded uncertainty of the average; time-averaged emission factors for a specific installation or of a family of installations and their associated uncertainty characteristics; a quality management system to assist the process of inventory quality assurance and verification. ISO 11771:2010 is applicable to the determination of emission factors for stationary sources including emissions from industrial processes where calculation from fuel and raw material is not practical, for greenhouse gases, and air pollutants including fine particulate material. ISO 11771:2010 does not address compliance monitoring in the context of emission control regulations. ISO 11771:2010 requires the use of measurement-based methods and calculation-based methods that use measurement data. It covers the planning and execution of the measurement programme to collect data, selection of sampling methods, calculation of results, estimation of uncertainty, determination of emission factors, and the reporting of information in a form that enables users to apply them. ISO 11771:2010 specifies how to: generate time-averaged mass emission rate data of a known quality, for a defined period of time, and a documented set of operational conditions; generate complete data sets representative of a known time period (i.e. a calendar year) by filling gaps in mass emission rate data series and combining data sets numerically; calculate emission factors for a known time period; calculate time-averaged emission factors of a known quality for a known source type. The measurement of emissions from vehicular, area or fugitive sources is not specifically covered. However, ISO 11771:2010 can be used for quantification of emission factors for those sources provided that measurements of emissions are available. ISO 11771:2010 does not explicitly include measurement procedures that are fully described in the referenced standards. Neither does it provide advice on the generation of activity statistics. ISO 11771:2010 is compatible with ISO 14064-1 and ISO 14064-3.

ISO 4226:2008 lays down the units to be used when reporting results of air quality measurements.

ISO 20988:2007 provides comprehensive guidance and specific statistical procedures for uncertainty estimation in air quality measurements including measurements of ambient air, stationary source emissions, indoor air, workplace atmospheres and meteorology. It applies the general recommendations of the Guide to the Expression of Uncertainty in Measurement (GUM) to boundary conditions met in air quality measurement. The boundary conditions considered include measurands varying rapidly in time, as well as the presence of bias in a series of observations obtained under conditions of intended use of methods of air quality measurement. The methods of measurement considered comprise methods corrected for systematic effects by repeated observation of reference materials, methods calibrated by paired measurement with a reference method, methods not corrected for systematic effects because they are unbiased by design, and methods not corrected for systematic effects in intended use deliberately taking into account a bias. Experimental data for uncertainty estimation can be provided either by a single experimental design in a direct approach or by a combination of different experimental designs in an indirect approach.

ISO 9169:2006 provides definitions and specifies methods to determine performance characteristics of an identified automatic air quality measuring system. Tests are carried out under stable laboratory conditions or field conditions. The automatic measuring system is considered as a black box operated according to specified procedures. ISO 9169:2006 applies to measuring systems for which the following information is available: a description of the automatic measuring system providing the result of measurement in the physical unit of the measurand; operating procedures of the automatic measuring system including, where appropriate, the procedures of routine adjustment, routine verification and calibration; terms of reference for the test program specifying the client requirements and test conditions. ISO 9169:2006 applies to measuring systems for which it is possible to apply several reference materials with accepted values with known uncertainty for the measurand, within the range of application. ISO 9169:2006 does not specify the number of automatic measuring systems to be tested.

This International Standard specifies, for the field of air quality measurement procedures, the: estimation of measurement uncertainty from actual or claimed values of all important performance characteristics of a method under stationary conditions; assessment of whether or not specified values for these performance characteristics comply with the required quality of a measured value at a stated measurand value; evaluation of the applicability of the measurement method based on laboratory performance and confirmatory field test; establishment of requirements on dynamic behaviour of instruments. This International Standard is applicable to measurement procedures whose output is a defined time average.

ISO 11222:2002 provides a method for the quantification of the uncertainty of a time average of a set of air quality data obtained at a specified location over a defined averaging time period. The method is applicable to air quality data obtained by continuous or intermittent monitoring by means of a specified measuring system. The uncertainty of the time average depends on both the uncertainty of the measurement results and the uncertainty due to incomplete time coverage of the data set. ISO 11222:2002 is only applicable if the set of air quality data used to calculate the time average is representative of the temporal structure of the measurand over the defined time period, appropriate information on the uncertainty of the measurement results is available, and the measurement results have all been obtained at the same location. ISO 11222:2002 implements recommendations of the Guide to the Expression of Uncertainty in Measurement (GUM).

Describes procedures for adjusting air quality measurements for changes in temperature, pressure and humidity during the sampling period. Specifies the reference conditions of temperature, pressure and humidity to be used when reporting the results. The procedures and reference conditions are applicable to air quality measurement methods and apply to measurements made in ambient and workplace atmospheres and to the measurement of stationary source emissions.

This is by estimating percentiles and means of the frequency distribution of measurements of characteristics. The application to the estimation of means is restricted to certain cases. The procedure enables results which are independent of the actual meteorological conditions prevailing during the interval of time of measurement to be calculated for a longer time.

Contains terms and definitions of performance characteristics related to air quality measuring methods. Does not include specific methods for determining air quality or obtaining representative samples.

Specifies procedures to quantify the performance characteristics of air quality measurement methods defined in ISO 6879: bias, calibration function and linearity, instability, lower detection limit, period of unattended operation, selectivity, sensitivity, upper limit of measurement. The procedures given are applicable only to air quality measurement methods with linear continuous calibration functions, the output variable of which is a defined time average.

Explains the meanings, in English and French, of a selection of terms commonly used in connection with the sampling and measurement of gases, vapours and particles for the determination. The terms are arranged in alphabetical order in English. An alphabetical index of the French terms is also given.

Lays down the units and symbols to be used when reporting results of measurements. For general guidance on the International System of Units, reference should be made to ISO 1000-1992.