BS ISO 17179:2016

Foreword
Introduction
1 Scope
2 Normative references
3 Terms and definitions
4 Symbols and abbreviated terms
5 Principle
6 Description of the automated measuring systems
7 Performance characteristics
8 Measurement procedure
9 Quality assurance and quality control procedures
10 Test report
Annex A (informative) - Extractive differential NO[x]
        measurement technique
Annex B (informative) - Extractive direct NH[3]
        measurement technique
Annex C (informative) - In situ and direct NH[3]
        measurement with TLS analyser
Annex D (normative) - Operational gases
Annex E (normative) - Procedures for determination of the
        performance characteristics during the general
        performance test
Annex F (informative) - Examples of the results for the
        assessment of ammonia AMS
Annex G (informative) - Calculation of uncertainty of
        measurement of NH[3]
Bibliography

Describes the fundamental structure and the most important performance characteristics of automated measuring systems for ammonia (NH[3]) to be used on stationary source emissions, for example, combustion plants where SNCR/SCR NOx control systems (deNOx systems) are applied.

This International Standard specifies the fundamental structure and the most important performance characteristics of automated measuring systems for ammonia (NH ₃) to be used on stationary source emissions, for example, combustion plants where SNCR/SCR NO _x control systems (deNO _x systems) are applied. The procedures to determine the performance characteristics are also specified. Furthermore, it describes methods and equipment to determine NH ₃ in flue gases including the sampling system and sample gas conditioning system.

This International Standard describes extractive systems, based on direct and indirect measurement methods, and in situ systems, based on direct measurement methods, in connection with a range of analysers that operate using, for example, the following principles:

• ammonia conversion to, or reaction with NO, followed by chemiluminescence (CL) NO _x difference measurement for ammonia (differential NO _x);

• ammonia conversion to, or reaction with NO, followed by non-dispersive ultraviolet (NDUV) spectroscopy NO _x difference measurement for ammonia (differential NO _x);

• Fourier transform infrared (FTIR) spectroscopy;

• non-dispersive infrared (NDIR) spectroscopy with gas filter correlation (GFC);

• tuneable laser spectroscopy (TLS).

The method allows continuous monitoring with permanently installed measuring systems of NH ₃ emissions, and is applicable to measurements of NH ₃ in dry or wet flue gases, for process monitoring, long term monitoring of the performance of deNO _x systems and/or emission monitoring.

Other equivalent instrumental methods can be used, provided they meet the minimum requirements proposed in this International Standard. The measuring system can be calibrated with certified gases, in accordance with this International Standard, or comparable methods.

The differential NO _x technique using CL has been successfully tested on some power plants where the NO _x concentration and NH ₃ concentration in flue gas after deNO _x systems are up to 50mg (NO)/m ³ and 10mg (NH ₃)/m ³, respectively. AMS based on FTIR, NDIR with GFC and TLS has been used successfully in this application for measuring ranges as low as 10mg (NH ₃)/m ³.