This International Standard specifies a test method for the measurement of exhaust gas opacity from compression-ignition (diesel-)engined vehicles. It describes the measurement of exhaust opacity under quasi-steady conditions during a lug-down at full load ?ver the normal operating speed range of the engine.
NOTE — This method is most suitable as an inspection station test. The test method with a steady single speed specified in ISO 7645 is also well suited to an inspection station test, but may be used on the road.
SIS SS-ISO 7644:1989 history
1989SIS SS-ISO 7644:1989 Road vehicles — Measurement of opacity of exhaust gas from compression-ignition (diesel) engines — Lug-down test