NBN ISO 8178-9:2021

Reciprocating internal combustion engines — Exhaust emission measurement — Part 9: Test cycles and test procedures for measurement of exhaust gas smoke emissions from compression ignition engines using an opacimeter (ISO 8178-9:2019)


About this standard

English and French
Publication date
08 June 2021
ICS Code
13.040.50 (Transport exhaust emissions)
27.020 (Internal combustion engines)

About this training


This document specifies the measurement procedures and test cycles for the evaluation of smoke
emissions from compression ignition engines using an opacimeter. The tests are carried out under
steady-state and transient operation using tests cycles which are representative of a given application.
The smoke testing is conducted using opacimeter-type smoke meters which operate on the light
extinction principle. The purpose of this document is to define the smoke test cycles and the methods
used to measure the opacity and for the determination of the light absorption coefficient. It allows the
use of either full-flow or partial-flow opacimeters and corrects for differences in rise time between
the two types of opacimeters. Specifications of the apparatus for the measurement of opacity can be
found in ISO 11614. The test procedures and measurement techniques described in this document are
applicable to reciprocating internal combustion (RIC) engines in general. Annex D, Annex E, Annex F
and Annex G each contains a test cycle that is relevant only for those specific applications listed in the
first subclause of that annex. Where possible, the smoke test cycle described in the annex utilizes the
engine and machine categories developed in ISO 8178-4.
For certain categories of non-road engines “at site” rather than “test bed” smoke test procedures
can prove to be necessary. For engines used in machinery covered by additional requirements (e.g.
occupational health and safety regulations), additional test conditions and special evaluation methods
can apply.