CEN/TC 264/WG 16 - Reference measurement methods for NOx, SO2, O2, CO and water vapour emissions

This European Standard specifies the Standard Reference Method (SRM) for sampling, and determining car-bon monoxide content in ducts and stacks emitting to atmosphere. It describes the Non Dispersive Infra-Red (NDIR) analytical technique, including the sampling system and sample gas conditioning system, to determine CO in flue gases. This European Standard is the reference method for periodic monitoring and for calibration or control of Automatic Measuring Systems (AMS) permanently installed on a stack, for regulatory purposes or other purposes. To be used as the SRM, it is necessary to demonstrate that the performance characteristics of the method are lower than the performance criteria defined in this European standard and that the overall uncertainty of the method is less than ± 6 % relative at the daily Emission Limit Value (ELV).
NOTE   When the NDIR method is used as an AMS, refer to EN 14181 and other relevant standards provided by CEN TC 264.
It is necessary for anybody who would like to use an Alternative Method instead of this Standard Reference Method to work out the demonstration of the equivalence according to the Technical Specification TS 14793, providing that his capability to carry out this demonstration is officially recognised by his national accreditation body or law.
   This Standard Reference Method has been evaluated during field tests on waste incineration, co-incineration installations and large combustion plants. It has been validated for CO concentrations with sampling periods of 30 min in the range of 0 mg/m3 to 400 mg/m3 for large combustion plants and 0 mg/m3 – 740 mg/m3 for waste and co-incineration. For waste incineration plants, Council Directive 2000/76/EC lays down emission values which are expressed in mg/m3, on dry basis at a specified value of O2 and at reference conditions of 273 K and 101,3 kPa.

This European Standard describes the chemiluminescence method, including the sampling and the gas conditioning system, to determine the NO/NO2/NOX concentrations in flue gases emitted from ducts and stacks to atmosphere. This European Standard is the Standard Reference Method (SRM) for periodic monitoring and for calibration or control of Automatic Measuring Systems (AMS) permanently installed on a stack, for regulatory or other purposes such as calibration. To be used as the SRM, the user shall demonstrate that the performance characteristics of the method are better than the performance criteria defined in this European Standard and that the overall uncertainty of the method is less than ± 10 percent relative at the daily Emission Limit Value (ELV).
NOTE   When the chemiluminescence method is the measurement principle used for AMS, reference should be made to EN 14181 and other relevant standards provided by CEN TC 264.
An Alternative Method to this SRM may be used provided that the user can demonstrate equivalence according to the Technical Specification CEN TS 14793, to the satisfaction of his national accreditation body or law.
This SRM has been evaluated during field tests on waste incineration, co-incineration and large combustion installations. It has been validated for sampling periods of 30 min in the range of 0 mgNO2/m3 to 1 300 mgNO2/m3 for large combustion plants and 0 mgNO2/m3 to 400 mgNO2/m3 for waste incineration, according to emission limit values (ELVs) laid down in the following Council Directives:
   Council Directive 2001/80/EC on the limitation of emissions of certain pollutants into the air from large combustion plants;
   Council Directive 2000/76/EC on waste incineration plants.
The ELVs for NOx (NO + NO2) in EU directives are expressed in mgNO2/m3, on dry basis, at a reference value for O2 and at the reference conditions (273 K and 101,3 kPa).

This European Standard describes the condensation/adsorption technique, including the sampling system, to determine the water vapour concentration in the flue gases emitting to atmosphere from ducts and stacks.
This technique is usually used all over Europe for water vapour monitoring. However to be implemented as the Standard Reference Method (SRM), the user has to demonstrate that the performance characteristics of the method are better than the performance criteria defined in this European Standard and that the overall uncertainty of the method is less than ± 20 percent of the measured value. This European Standard as the Standard Reference Method (SRM) is used for periodic monitoring and for calibration or control of Automatic Measuring Systems (AMS) permanently installed on a stack, for regulatory purposes or other purposes.
An Alternative Method to this SRM may be used provided that the user can demonstrate equivalence according to the Technical Specification CEN/TS 14793, to the satisfaction of his national accreditation body or law.
The determination of water vapour is mainly necessary for:
   regulatory purposes, to express the concentration at standard conditions (on dry gas);
   adjust the flow rate for isokinetic sampling, when a dry gas flow rate metering device is used.
For both applications, the quantity to be measured is the amount of water present in the gas phase (vapour), which does not include water droplets.
This European Standard is applicable in the range from 4 percent to 40 percent relative humidity and for water vapour concentration from 29 g/m3 to 250 g/m3 as a wet gas, although for a given temperature the upper limit of the method is related to the maximum pressure of water in air or in the gas.
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This European Standard describes the paramagnetic method, including the sampling and the gas conditioning system, to determine the oxygen concentrations in flue gases emitted to the atmosphere from ducts and stacks.
This European Standard is the Standard Reference Method (SRM) for periodic monitoring and for the calibration or control of Automatic Measuring Systems (AMS) permanently installed on a stack, for regulatory purposes or other purposes. To be used as the SRM, the user shall demonstrate that the performance characteristics of the method are better than the performance criteria defined in this European Standard and that the overall uncertainty of the method is less than ± 6,0 percent of the measured concentration.
NOTE   When paramagnetism is the measurement principle used for AMS, reference should be made to EN 14181 and other relevant standards provided by CEN/TC 264.
An alternative method to this SRM may be used provided that the user can demonstrate equivalence according to the Technical Specification CEN/TS 14793, to the satisfaction of his national accreditation body or law.
This Standard Reference Method has been evaluated during field tests on waste incineration, co-incineration and large combustion installations. It has been validated for sampling periods of 30 min in the range: 5 percent to 26 percent. Oxygen concentration values, expressed in percent volume, are used in order to allow emission measurements of pollutants to be standardised to the reference O2 concentration and dry gas conditions required by the following Council Directives:
   Council Directive 2001/80/EC on the limitation of emissions of certain pollutants into the air from large combustion plants;
   Council Directive 2000/76/EC on waste incineration plants.

This European Standard describes a manual method for sampling and determining SO2 content in ducts and stacks emitting to the atmosphere by two analytical methods: Ion chromatography and Thorin method.
This European Standard is the Standard Reference Method (SRM) for periodic monitoring and for calibration or control of Automatic Measuring Systems (AMS) permanently installed on a stack, for regulatory purposes or other purposes. To be used as the SRM, the user shall demonstrate that the performance characteristics of the method are better than the performance criteria defined in this European Standard and that the overall uncertainty of the method is less than ± 20,0 % relative at the daily Emission Limit Value (ELV).
An Alternative Method to this SRM may be used provided that the user can demonstrate equivalence according to the Technical Specification CEN TS 14793, to the satisfaction of his national accreditation body or law.
This Standard Reference Method has been evaluated during field tests on waste incineration, co-incineration and large combustion installations. It has been validated for sampling periods of 30 min in the range of (0,5   2 000) mg/m3 SO2 for Ion Chromatography variant and 5 mg/m3 - 2 000 mg/m3 SO2 for Thorin method according to emission limit values laid down in the following Council Directives:
¾   Council Directive 2001/80/EC on the limitation of emissions of certain pollutants into the air from large combustion plants;
¾   Council Directive 2000/76/EC on waste incineration plants.
The limit values of EU Directives are expressed in mg SO2/m3, on dry basis and at the reference conditions of 273 K and 101,3 kPa.

The purpose of this technical specification is to specify a validation procedure to show if an Alternative Method (AM) can be used as an alternative to the Standard Reference Method (SRM), both implemented to determine the same measurand. This document has been drawn up for laboratories working in air pollution measurements (and consequently examples taken from this sector are included in the appendices).
In particular, this Technical Specification provides the statistical tools and different criteria to evaluate the alternative method; this does not release the person responsible for this validation from bearing technical and analytical judgement on the evaluation of the different criteria.
Three steps are described in the validation procedure:
-   description of the AM and setting of the field of equivalence (range and type of gas matrix);
-   determination of the performance characteristics of the AM and calculation of the overall uncertainty where appropriate and check of compliance of the maximum overall uncertainty allowed for the SRM;
-   check of repeatability and lack of systematic deviation of the AM in the field in comparison with the SRM for the type of matrix defined in the field of equivalence.
NOTE   Some parts of the second step of the validation of the alternative method should be performed by a recognised test-house.
If the AM fulfils the requirement of the procedure, then the laboratory that carried out the whole validation process is allowed to use it as a SRM in the field application where the equivalence has been demonstrated.
However, if the validation process involves at least 4 different accredited laboratories performing simultaneously parallel measurements in the field, and if the AM passes with success all the tests of the procedure, then this method could be proposed to CEN, who can decide to consider this AM as a new reference method (ARM).
The use of this procedure implies that a reference method has been defined by the regulator or i