General specifications for catalytic converters of motorcycles and mopeds
1 Scope
This standard specifies the requirements, test methods, inspection rules as well as marking, packaging, transportation and storage for catalytic converters of motorcycles and mopeds.
This standard is applicable to catalytic converters of motorcycles and mopeds (hereinafter referred to as “catalytic converters”).
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated references, subsequent amendments (excluding corrections) to, or revisions of any of these publications do not apply to this standard. However parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition applies.
GB/T 5181 Automotive emission - Terms and definitions
GB/T 8190-1999 Reciprocating internal combustion engines - Exhaust emission measurement
GB/T 18377 Requirements and measurement methods of catalytic converters for petrol vehicles
3 Terms and definitions
For the purposes of this standard, the terms and definitions given in GB/T 5181 and GB/T 18377 and the following apply.
3.1
conversion ratio (η)
ratio of the concentration change of a component in exhaust gas before and after flowing through the catalytic converter to the concentration of the component at the inlet of the catalytic converter
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where,
η——the conversion ratio, %;
C——the volume concentration of pollutants;
i——the inlet of catalytic converter;
e——the outlet of catalytic converter;
j——the appropriate description of pollutants CO, HC, NOX or other components respectively.
3.2
oxygen balance coefficient (β)
in case of simulating the engine exhaust gas with standard materials, the oxygen balance coefficient β represents the nature of atmosphere environment. Oxygen balance coefficient is defined as the ratio of the volume concentration of oxygen contained in the simulated exhaust gas to the oxygen concentration required for complete oxidation of harmful gases containing carbon in the exhaust gas
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Requirements
5 Marking, packaging, transportation and storage
Annex A (Normative) Test method for catalyst activity in simulated exhaust gas environment
Annex B (Normative) Test method for catalyst weight loss ratio
Annex C (Normative) Test method for thermal vibration of catalytic converter
