CEN/TC 264/WG 12 - Reference method for determination of SO2/NO2/O3/CO in ambient air

This document gives general guidance for the sampling and analysis of benzene in air by pumped sampling, thermal desorption and capillary gas chromatography.
This document is in accordance with the generic methodology selected as the basis of the European Union reference method for the determination of benzene in ambient air [1] for the purpose of comparison of measurement results with limit values with a one-year reference period.
This document is valid for the measurement of benzene in a concentration range of approximately 0,5 μg/m3 to 50 μg/m3. Air samples are typically collected over periods ranging from a few hours to 7 days.
The upper limit of the useful range is set by the sorptive capacity (the safe sampling volume) of the sorbent and by the linear dynamic range of the gas chromatograph column and detector or by the sample splitting capacity of the analytical instrumentation used. The lower limit of the useful range depends on the noise level of the detector and on blank levels of benzene and/or interfering artefacts on the sorbent. Artefacts are typically sub ng for graphitised carbon sorbents, but higher levels of aromatic hydrocarbons have been noted in other sorbents - e.g. porous polymers. The detection limit will be approximately 1/10 of the lower concentration range.
This document provides general guidance for the sampling of benzene using either a single sampler, which is changed manually after every exposure period, or a multi-sampler capable of storing and exposing multiple samples without user intervention.

This European Standard specifies a semi-continuous measurement method for the determination of the concentration of benzene present in ambient air based on automated sampling and analysis by gas chromatography. This standard describes the performance characteristics and sets the relevant minimum criteria required to select an appropriate automated gas chromatograph (GC) by means of type approval tests. It also includes the evaluation of the suitability of an analyser for use in a specific fixed site so as to meet the data quality requirements as specified in Annex I of Directive 2008/50/EC [1] and requirements during sampling, calibration and quality assurance for use.
The method is applicable to the determination of the mass con¬centration of benzene present in ambient air in the range up to 50 µg/m3 benzene. This concentration range represents the certification range for the type approval test.
Other ranges may be used depending on the levels present in ambient air.
NOTE 1   When the standard is used for other purposes than for measurements required by Directive 2008/50/EC, the ranges and uncertainty requirements may not apply.
The method covers the determination of ambient air concentrations of benzene in zones classified as rural areas, urban-background areas and traffic-orientated locations and locations influenced by industrial sources.
The results are expressed in µg/m3 (at 20 °C and 101,3 kPa).
NOTE 2   50 µg/m3 of benzene corresponds to 15,4 nmol/mol of benzene.
This European Standard contains information for different groups of users.
Clauses 5 to 7 and Annexes C and D contain general information about the principles of benzene measurement by automated gas chromatography and sampling equipment.
Clause 8 and Annex E are specifically directed towards test houses and laboratories that perform type-approval testing of benzene analysers. These sections contain information about:
-   type-approval test conditions, test procedures and test requirements;
-   analyser performance requirements;
-   evaluation of the type-approval test results;
-   evaluation of the uncertainty of the measurement results of the benzene analyser based on the type-approval test results.
Clauses 9 to 11 and Annex F are directed towards monitoring networks performing the practical measurements of benzene in ambient air. These sections contain information about:
-   initial installation of the analyser in the monitoring network and acceptance testing;
-   ongoing quality assurance/quality control;
-   calculation and reporting of measurement results;
-   evaluation of the uncertainty of measurement results under practical monitoring conditions.

CEN/TC 264 origin - Editorial modifications in the Englsih + French reference versions only. (Changes were not necessary on the German ref. version as they had already been implemented in it.)

This European Standard specifies a continuous measurement method for the determination of the concentration of carbon monoxide present in ambient air based on the non-dispersive infrared spectroscopic measuring principle. This standard describes the performance characteristics and sets the relevant minimum criteria required to select an appropriate non-dispersive infrared spectroscopic analyser by means of type approval tests. It also includes the evaluation of the suitability of an analyser for use in a specific fixed site so as to meet the data quality requirements as specified in Annex I of Directive 2008/50/EC [1] and requirements during sampling, calibration and quality assurance for use.
The method is applicable to the determination of the mass con¬centration of carbon monoxide present in ambient air up to 100 mg/m3 carbon monoxide. This concentration range represents the certification range for CO for the type approval test.
NOTE 1   Other ranges may be used depending on the levels present in ambient air.
NOTE 2   When the standard is used for other purposes than for measurements required by Directive 2008/50/EC, the ranges and uncertainty requirements may not apply.
The method covers the determination of ambient air concentrations of carbon monoxide in areas classified as rural, urban-background and traffic-orientated and those influenced by industrial sources.  
The results are expressed in mg/m3 (at 20 °C and 101,3 kPa).
NOTE 3   100 mg/m3 of CO corresponds to 86 mol/mol of CO.
This standard contains information for different groups of users.
Clauses 5 to 7 and Annexes B, C and D contain general information about the principles of carbon monoxide measurement by non-dispersive infrared spectroscopic analyser and sampling equipment.
Clause 8 and Annex E are specifically directed towards test houses and laboratories that perform type-approval testing of carbon monoxide analysers. These sections contain information about:
-   Type-approval test conditions, test procedures and test requirements;
-   Analyser performance requirements;
-   Evaluation of the type-approval test results;
-   Evaluation of the uncertainty of the measurement results of the carbon monoxide analyser based on the type-approval test results.
Clauses 9 to 11 and Annex F are directed towards monitoring networks performing the practical measurements of carbon monoxide in ambient air. These sections contain information about:
-   Initial installation of the analyser in the monitoring network and acceptance testing;
-   Ongoing quality assurance/quality control;
-   Calculation and reporting of measurement results;
-   Evaluation of the uncertainty of measurement results under practical monitoring conditions.

This European Standard specifies a continuous measurement method for the determination of the concentrations of nitrogen dioxide and nitrogen monoxide present in ambient air based on the chemiluminescence measuring principle. This standard describes the performance characteristics and sets the relevant minimum criteria required to select an appropriate chemiluminescence analyser by means of type approval tests. It also includes the evaluation of the suitability of an analyser for use in a specific fixed site so as to meet the data quality requirements as specified in Annex I of Directive 2008/50/EC [1] and requirements during sampling, calibration and quality assurance for use.
The method is applicable to the determination of the concentration of nitrogen dioxide present in ambient air up to 500 µg/m3. This concentration range represents the certification range for NO2 for the type approval test.
The method is applicable to the determination of the concentration of nitrogen monoxide present in ambient air up to 1 200 µg/m3. This concentration range represents the certification range for NO for the type approval test.
NOTE 1   It is possible to use other ranges depending on the levels present in ambient air.
NOTE 2   When this European Standard is used for other purposes than for measurements required by Directive 2008/50/EC, the ranges and uncertainty requirements may not apply.
The method covers the determination of ambient air concentrations of nitrogen dioxide and nitrogen monoxide in zones classified as rural areas, urban-background areas and traffic-orientated locations and locations influenced by industrial sources.
The results are expressed in µg/m3 (at 20 °C and 101,3 kPa).
NOTE 3   500 µg/m3 of NO2 corresponds to 261 nmol/mol of NO2 at 20 °C and 101,3 kPa. 1 200 µg/m3 of NO corresponds to 962 nmol/mol of NO at 20 °C and 101,3 kPa.
This standard contains information for different groups of users.
Clauses 5 to 7 and Annexes B and C contain general information about the principles of NOx measurement by chemiluminescence analyser and sampling equipment.
Clause 8 and Annex E are specifically directed towards test houses and laboratories that perform type-approval testing of NOx analysers. These sections contain information about:
-   Type-approval test conditions, test procedures and test requirements;
-   Analyser performance requirements;
-   Evaluation of the type-approval test results;
-   Evaluation of the uncertainty of the measurement results of the NOx analyser based on the type-approval test results.
Clauses 9 to 11 and Annexes F and G are directed towards monitoring networks performing the practical measurements of NOx in ambient air. These sections contain information about:
-   Initial installation of the analyser in the monitoring network and acceptance testing;
-   Ongoing quality assurance/quality control;
-   Calculation and reporting of measurement results;
-   Evaluation of the uncertainty of measurement results under practical monitoring conditions.

This European Standard specifies a continuous measurement method for the determination of the concentration of sulphur dioxide present in ambient air based on the ultraviolet fluorescence measuring principle. This standard describes the performance characteristics and sets the relevant minimum criteria required to select an appropriate ultraviolet fluorescence analyser by means of type approval tests. It also includes the evaluation of the suitability of an analyser for use in a specific fixed site so as to meet the data quality requirements as specified in Annex I of Directive 2008/50/EC [1] and requirements during sampling, calibration and quality assurance for use.
The method is applicable to the determination of the mass concentration of sulphur dioxide present in ambient air up to 1000 µg/m3. This concentration range represents the certification range for SO2 for the type approval test.
NOTE 1   Other ranges may be used depending on the levels present in ambient air.
NOTE 2   When the standard is used for other purposes than for measurements required by Directive 2008/50/EC, the ranges and uncertainty requirements may not apply.
The method covers the determination of ambient air concentrations of sulphur dioxide in zones classified as rural areas, urban-background areas and traffic-orientated locations and locations influenced by industrial sources.
The results are expressed in µg/m3 (at 20 °C and 101,3 kPa).
NOTE 3   1000 µg/m3 of SO2 corresponds to 376 nmol/mol of SO2.
This standard contains information for different groups of users.
Clauses 5 to 7 and Annexes C and D contain general information about the principles of sulphur dioxide measurement by ultraviolet fluorescence analyser and sampling equipment.
Clause 8 and Annex E are specifically directed towards test houses and laboratories that perform type-approval testing of sulphur dioxide analysers. These sections contain information about:
-   Type-approval test conditions, test procedures and test requirements;
-   Analyser performance requirements;
-   Evaluation of the type-approval test results;
-   Evaluation of the uncertainty of the measurement results of the sulphur dioxide analyser based on the type-approval test results.
Clauses 9 to 11 and Annexes F and G are directed towards monitoring networks performing the practical measurements of sulphur dioxide in ambient air. These sections contain information about:
-   Initial installation of the analyser in the monitoring network and acceptance testing;
-   Ongoing quality assurance/quality control;
-   Calculation and reporting of measurement results;
-   Evaluation of the uncertainty of measurement results under practical monitoring conditions.

This European Standard specifies a continuous measurement method for the determination of the concentrations of ozone present in ambient air based on the ultraviolet photometric measuring principle. This standard describes the performance characteristics and sets the relevant minimum criteria required to select an appropriate ultraviolet photometric analyser by means of type approval tests. It also includes the evaluation of the suitability of an analyser for use in a specific fixed site so as to meet the data quality requirements as specified in Annex I of Directive 2008/50/EC [1] and requirements during sampling, calibration and quality assurance for use.
The method is applicable to the determination of the con¬centration of ozone present in ambient air up to 500 µg/m3. This concentration range represents the certification range for ozone for the type approval test.
NOTE 1   Other ranges may be used depending on the levels present in ambient air.
NOTE 2   When the standard is used for other purposes than for measurements required by Directive 2008/50/EC, the ranges and uncertainty requirements may not apply.
The method covers the determination of ambient air concentrations of ozone in areas classified as rural, urban and urban-background areas.
The results are expressed in µg/m3 (at 20 C and 101,3 kPa).
NOTE 3   500 µg/m3  of  O3 corresponds to 250 nmol/mol of O3 at 20 C and 101,3 kPa.
This standard contains information for different groups of users.
Clauses 5 to 7 and Annexes B and C contain general information about the principles of ozone measurement by ultraviolet photometric analyser and sampling equipment.
Clause 8 and Annex E are specifically directed towards test houses and laboratories that perform type-approval testing of ozone analysers. These sections contain information about:
-   Type-approval test conditions, test procedures and test requirements;
-   Analyser performance requirements;
-   Evaluation of the type-approval test results;
-   Evaluation of the uncertainty of the measurement results of the ozone analyser based on the type-approval test results.
Clauses 9 to 11 and Annexes F and G are directed towards monitoring networks performing the practical measurements of ozone in ambient air. These sections contain information about:
-   Initial installation of the analyser in the monitoring network and acceptance testing;
-   Ongoing quality assurance/quality control;
-   Calculation and reporting of measurement results;
-   Evaluation of the uncertainty of measurement results under practical monitoring conditions.

This document specifies a continuous measurement method for the determination of the concentrations of nitrogen dioxide and nitrogen monoxide present in ambient air based on the chemiluminescence measuring principle. This document describes the performance characteristics and sets the relevant minimum criteria required to select an appropriate chemiluminescence analyser by means of type testing. It also includes the evaluation of the suitability of an analyser for use in a specific fixed site so as to meet the data quality requirements as specified in Annex I of Directive 2008/50/EC [1] and requirements during sampling, calibration and quality assurance for use.
The method is applicable to the determination of the concentration of nitrogen dioxide present in ambient air up to 500 µg/m3. This concentration range represents the certification range for nitrogen dioxide for type testing.
The method is applicable to the determination of the concentration of nitrogen monoxide present in ambient air up to 1 200 µg/m3. This concentration range represents the certification range for nitrogen monoxide for the type testing.
NOTE 1   It is possible to use other ranges depending on the levels present in ambient air.
NOTE 2   When this document is used for purposes other than for measurements required by Directive2008/50/EC, the ranges and uncertainty requirements possibly do not apply.
The method covers the determination of ambient air concentrations of nitrogen dioxide and nitrogen monoxide in zones classified as rural areas, urban-background areas, traffic-orientated locations and locations influenced by industrial sources.
The results are expressed in µg/m3 (at 20 °C and 101,3 kPa).
NOTE 3   500 µg/m3 of nitrogen dioxide corresponds to 261 nmol/mol of nitrogen dioxide at 20 °C and 101,3 kPa. 1 200 µg/m3 of nitrogen monoxide corresponds to 962 nmol/mol of nitrogen monoxide at 20 °C and 101,3 kPa.
This document contains information for different groups of users.
Clause 5 to Clause 7 and Annex B and Annex C contain general information about the principles of NOx measurement by chemiluminescence analyser and sampling equipment.
Clause 8 and Annex E are specifically directed towards test houses and laboratories that perform type testing of NOx analysers. These sections contain information about:
—   type testing conditions, test procedures and test requirements;
—   analyser performance requirements;
—   evaluation of the type testing results;
—   evaluation of the uncertainty of the measurement results of the NOx analyser based on the type testing results.
Clause 9 to Clause 11 and Annex F and Annex G are directed towards monitoring networks performing the practical measurements of NOx in ambient air. These sections contain information about:
—   initial installation of the analyser in the monitoring network and acceptance testing;
—   ongoing quality assurance/quality control;
—   calculation and reporting of measurement results;
—   evaluation of the uncertainty of measurement results under practical monitoring conditions.
This document represents an evolution of earlier editions (EN 14211:2005 and EN 14211:2012). It is advisable that when equipment is procured it complies fully with this document.
NOTE 4   Type testing performed prior to the publication of this document for the purpose of demonstrating equivalence are still valid.
NOTE 5   Analysers type tested prior to the publication of this document remain valid for use for regulated monitoring purposes.

This European Standard specifies a continuous measurement method for the determination of the concentration of carbon monoxide present in ambient air based on the non-dispersive infrared spectroscopic measuring principle.
This standard describes the performance characteristics and sets the relevant minimum criteria required to select an appropriate non-dispersive infrared spectroscopic analyser by means of type approval tests. It also includes the evaluation of the suitability of an analyser for use in a specific fixed site so as to meet the data quality requirements as specified in Annex I of Directive 2008/50/EC [1] and requirements during sampling, calibration and quality assurance for use.
The method is applicable to the determination of the mass concentration of carbon monoxide present in ambient air up to 100 mg/m3 carbon monoxide. This concentration range represents the certification range for the type approval test.
NOTE 1 Other ranges may be used depending on the levels present in ambient air.
NOTE 2 When the standard is used for other purposes than for measurements required by Directive 2008/50/EC, the ranges and uncertainty requirements may not apply.
The method covers the determination of ambient air concentrations of carbon monoxide in zones classified as rural areas, urban-background areas and traffic-orientated locations and locations influenced by industrial sources.
The results are expressed in mg/m3 (at 20 °C and 101,3 kPa).
NOTE 3 100 mg/m3 of CO corresponds to 86 μmol/mol of CO.
This standard contains information for different groups of users.
Clauses 5 to 7 and Annexes B, C and D contain general information about the principles of carbon monoxide measurement by non-dispersive infrared spectroscopic analyser and sampling equipment.
Clause 8 and Annex E are specifically directed towards test houses and laboratories that perform type-approval testing of carbon monoxide analysers. These sections contain information about:
− type-approval test conditions, test procedures and test requirements;
− analyser performance requirements;
− evaluation of the type-approval test results;
− evaluation of the uncertainty of the measurement results of the carbon monoxide analyser based on the type approval test results.
Clauses 9 to 11 and Annex F are directed towards monitoring networks performing the practical measurements of carbon monoxide in ambient air. These sections contain information about:
− initial installation of the analyser in the monitoring network and acceptance testing;
− ongoing quality assurance/quality control;
− calculation and reporting of measurement results;
− evaluation of the uncertainty of measurement results under practical monitoring conditions.

This document specifies a continuous measurement method for the determination of the concentration of sulfur dioxide present in ambient air based on the ultraviolet fluorescence measuring principle. This document describes the performance characteristics and sets the relevant minimum criteria required to select an appropriate ultraviolet fluorescence analyser by means of type testing. It also includes the evaluation of the suitability of an analyser for use in a specific fixed site so as to meet the data quality requirements as specified in Annex I of Directive 2008/50/EC [1] and requirements during sampling, calibration and quality assurance for use.
The method is applicable to the determination of the mass concentration of sulphur dioxide present in ambient air up to 1000 µg/m3. This concentration range represents the certification range for sulfur dioxide for type testing.
NOTE 1   It is possible to use other ranges depending on the levels present in ambient air.
NOTE 2   When this document is used for purposes other than for measurements required by Directive 2008/50/EC, the ranges and uncertainty requirements possibly do not apply.
The method covers the determination of ambient air concentrations of sulfur dioxide in locations classified as rural areas, urban-background areas, and for sampling influenced by traffic or industrial sources.
The results are expressed in µg/m3 (at 20 °C and 101,3 kPa).
NOTE 3   1 000 µg/m3 of SO2 corresponds to 376 nmol/mol of SO2.
This document contains information for different groups of users.
Clause 5 to Clause 7 and Annex C and Annex D contain general information about the principles of sulfur dioxide measurement by ultraviolet fluorescence analyser and sampling equipment.
Clause 8 and Annex E are specifically directed towards test houses and laboratories that perform type testing of sulfur dioxide analysers. These sections contain information about:
—   type testing conditions, test procedures and test requirements;
—   analyser performance requirements;
—   evaluation of the type testing results;
—   evaluation of the uncertainty of the measurement results of the sulfur dioxide analyser based on the type testing results.
Clause 9 to Clause 11 and Annex F and Annex G are directed towards monitoring networks performing the practical measurements of sulfur dioxide in ambient air. These sections contain information about:
—   initial installation of the analyser in the monitoring network and acceptance testing;
—   ongoing quality assurance/quality control;
—   calculation and reporting of measurement results;
—   evaluation of the uncertainty of the measurement results under practical monitoring conditions.
This document represents an evolution of earlier editions (EN 14212:2005 and EN 14212:2012). It is advisable that when equipment is procured it complies fully with this document.
NOTE 4   Type testing performed prior to the publication of this document for the purpose of demonstrating equivalence are still valid.
NOTE 5   Analysers type tested prior to the publication of this document remain valid for use for regulated monitoring purposes.

This European Standard specifies a continuous measurement method for the determination of the concentrations of ozone present in ambient air based on the ultraviolet photometric measuring principle. This standard describes the performance characteristics and sets the relevant minimum criteria required to select an appropriate ultraviolet photometric analyser by means of type approval tests. It also includes the evaluation of the suitability of an analyser for use in a specific fixed site so as to meet the data quality requirements as specified in Annex I of Directive 2008/50/EC [1] and requirements during sampling, calibration and quality assurance for use.
The method is applicable to the determination of the concentration of ozone present in ambient air up to 500 μg/m3.
This concentration range represents the certification range for ozone for the type approval test.
NOTE 1 Other ranges may be used for measurement systems applied at rural locations monitoring ecosystems.
NOTE 2 When the standard is used for other purposes than Directive 2008/50/EC, the ranges and uncertainty requirements may not apply.
The method covers the determination of ambient air concentrations of ozone in zones classified as rural areas, urban and urban-background areas.
The results are expressed in μg/m3 (at 20 °C and 101,3 kPa).
NOTE 3 500 μg/m3 of O3 corresponds to 250 nmol/mol of O3 at 20 °C and 101,3 kPa.
This standard contains information for different groups of users.
Clauses 5 to 7 and Annexes B and C contain general information about the principles of ozone measurement by ultraviolet photometric analyser and sampling equipment.
Clause 8 and Annex E are specifically directed towards test houses and laboratories that perform type-approval testing of ozone analysers. These sections contain information about:
− type-approval test conditions, test procedures and test requirements;
− analyser performance requirements;
− evaluation of the type-approval test results;
− evaluation of the uncertainty of the measurement results of the ozone analyser based on the type-approval test results.
Clauses 9 to 11 and Annexes F and G are directed towards monitoring networks performing the practical
measurements of ozone in ambient air. These sections contain information about:
− initial installation of the analyser in the monitoring network and acceptance testing;
− ongoing quality assurance/quality control;
− calculation and reporting of measurement results;
− evaluation of the uncertainty of measurement results under practical monitoring conditions.

This document specifies a continuous measurement method for the determination of the concentration of nitrogen dioxide and nitrogen monoxide present in ambient air based on the chemiluminescence measuring principle. This document describes the performance characteristics and sets the relevant minimum criteria required to select an appropriate chemiluminescence analyser by means of type approval tests. It also includes the evaluation of the suitability of an analyser for use in a specific fixed site so as to meet the Directives data quality requirements and requirements during sampling, calibration and quality assurance.
The method is applicable to the determination of the concentration of nitrogen dioxide present in ambient air from 0 mg/m3 to 500 mg/m3. This concentration range represents the certification range for NO2 for the type approval test.
NOTE 1   0 mg/m3 to 500 mg/m3 of NO2 corresponds to 0 nmol/mol to 261 nmol/mol of NO2.
The method is applicable to the determination of the concentration of nitrogen monoxide present in ambient air from 0 mg/m3 to 1 200 mg/m3. This concentration range represents the certification range for NO for the type approval test.
NOTE 2   0 mg/m3 to 1 200 mg/m3 of NO corresponds to 0 nmol/mol to 962 nmol/mol of NO.
The method covers the determination of ambient air concentrations of nitrogen dioxide and nitrogen monoxide in zones classified as rural areas, urban-background areas and traffic-orientated locations.
NOTE 3   Lower ranges may be used for measurement systems applied at rural locations monitoring Ecosystems.
The results are expressed in mg/m3 (at 293 K and 101,3 kPa).
When the standard is used for other purposes than the EU Directive, the range and uncertainty requirements need not apply.

This document specifies a continuous measurement method for the determination of the concentration of sulphur dioxide present in ambient air based on the ultraviolet fluorescence measuring principle. This document describes the performance characteristics and sets the relevant minimum criteria required to select an appropriate ultraviolet fluorescence analyser by means of type approval tests. It also includes the evaluation of the suitability of an anayser for use in a specific fixed site so as to meet the Directives data quality requirements and requirements during sampling, calibration and quality assurance for use.
The method is applicable to the determination of the mass concentration of sulphur dioxide present in ambient air from 0 mg/m3 to 1 000 mg/m3 sulphur dioxide. This concentration range represents the certification range for the type approval test.
NOTE 1   0 mg/m3 to 1 000 mg/m3 of SO2 corresponds to 0 nmol/mol to 376 nmol/mol of SO2.
NOTE 2   Lower ranges may be used for measurement systems applied at rural locations monitoring Ecosystems.
The method covers the determination of ambient air concentrations of sulphur dioxide in zones classified as rural areas, urban-background areas and traffic-orientated locations.
The results are expressed in mg/m3 (at 293 K and 101,3 kPa).
When the standard is used for other purposes than the EU-directive, the range and uncertainty requirements need not apply.

This document specifies a continuous measurement method for the determination of the concentration of carbon monoxide present in ambient air based on the non-dispersive infrared measuring principle (NDIR). This document describes the performance characteristics and sets the relevant minimum criteria required to select an appropriate non-dispersive infrared carbon monoxide analyser by means of type approval tests. It also includes the evaluation of the suitability of an anayser for use in a specific fixed site so as to meet the Directives data quality requirements and requirements during sampling, calibration and quality assurance.
The method is applicable to the determination of the mass concentration of carbon monoxide present in ambient air in the range from 0 mg/m3 to 100 mg/m3 carbon monoxide. This concentration range represents the certification range for the type approval test.
NOTE 1   0 mg/m3 to 100 mg/m3 of CO corresponds to 0 mmol/mol to 86 mmol/mol of CO.
The method covers the determination of ambient air concentrations of carbon monoxide in zones classified as rural areas, urban-background areas and traffic-orientated locations.
NOTE 2   Other ranges may be used for measurement systems applied at rural locations monitoring Ecosystems.
The results are expressed in mg/m3 (at 293 K and 101,3 kPa).
When the standard is used for other purposes than the EU directive, the range and uncertainty requirements need not apply.

This document specifies a continuous measurement method for the determination of the concentration of ozone present in ambient air based on the ultraviolet photometric measuring principle. This document describes the performance characteristics, and sets the relevant minimum criteria required to select an appropriate ultraviolet photometric ozone analyser by means of type approval tests. It also includes the evaluation of the suitability of an anayser for use in a specific fixed site so as to meet the Directives data quality requirements and requirements during sampling, calibration and quality assurance.
The method is applicable to the determination of the mass concentration of ozone present in ambient air in the range from 0 mg/m3 to 500 mg/m3. This concentration range represents the certification range for the type approval test.
NOTE 1   0 mg/m3 to 500 mg/m3 of O3 corresponds to 0 nmol/mol to 250 nmol/mol of O3.
The method covers the determination of ambient air concentrations of ozone in zones classified as rural areas, urban and urban-background areas.
NOTE 2   Other ranges may be used for measurement systems applied at rural locations monitoring Ecosystems.
The results are expressed in mg/m3 (at 20 °C and 101,3 kPa).
When the standard is used for other purposes than the EU-directive, the range and uncertainty requirements need not apply.