BS ISO 8178-1:2020 pdf download.Reciprocating internal combustion engines - Exhaust emission measurement.
5 General measurement principles
The emission of gaseous and particulate components by the engine submitted for testing shall be
measured by the methods described in Clauses 6 to 8 . These clauses describe the engine and ambient
related measurement systems ( Clause 6 ) , the analytical systems for the gaseous emissions ( Clause 7 )
and the particulate sampling systems ( Clause 8 ) . The system calibration procedures are described in
Clause 9
Test cycles and emissions calculations are not part of this document . They are included in I $ 0 8178-4
Other systems or analysers may be accepted if they yield equivalent results . The determination of
system equivalency shall be based on a seven-sample pair ( or larger ) correlation study between the
system under consideration and one of the accepted systems of this document . Results " refers to
the specific cycle weighted emissions value . The correlation testing is to be performed at the same
laboratory , test cell , and on the same en gine . The tests should be run concurrently . The test cycle to be
used shall be the appropriate cycle as found in ISO 8178-4 . The equivalency of the sample pair averages
shall be determined by F-test and t-test statistics ( see Annex D ) , with outliers excluded , obtained under
testing shall be declared prior to the test and shalbe agreed upon by the parties inv / / " r correlation
the laboratory cell and the engine conditions described above . The systems to be used for
For introduction of a new system into this document , the determination of equivalency shall be based
upon the calculation of repeatability and reproducibility , as described in 1S0 5725-2
5.1 Principle of emission measurement
To measure the brake-specific emissions the engine shall be operated over the test cycles defined in
S0 8178-4 , as applicable . The measurement of brake-specific emissions requires the determination of
the mass of pollutants in the exhaust and the corresponding engine work .
5.1.1 Mass of constituent
The total mass of each constituent shall be determined over the applicable test cycle by using the
following method
5.1.1.1 Continuous sampling
In continuous sampling , the constituents concentration is measured continuously from raw or dilute
exhaust . This concentration is multiplied by the continuous ( raw or diluted ) exhaust flow rate at the
emission sampling location to determine the constituents flow rate . The constituents emission is
continuously summed over the test interval . This sum is the total mass of the emitted constituent
5.1.1.2 Batch sampling
In batch sampling , a sample of raw or dilute exhaust is continuously extracted and stored for later
measurement . The extracted sample shall be proportional to the raw or dilute exhaust flow rate
Examples of batch sampling are collecting diluted gaseous emissions in a bag and collecting PM on a filter
In principal the method of emission calculation is done as follows : the batch sampled concentrations
are multiplied by the total mass or mass flow ( raw or dilute ) from which it was extracted during the
test cycle . This product is the total mass or mass flow of the emitted constituent . To calculate the PM
concentration , the PM deposited onto a filter from proportionally extracted exhaust shall be divided by
the amount of filtered exhaust
5.1.1.3 Combined sampling
Any combination of continuous and batch sampling is permitted ( e.g. PM with batch sampling and
gaseous emissions with continuous sampling )
Ligure 2 illustrates the two aspects of the test procedures for measuring emissions : the equipment
with the sampling lines in raw and diluted exhaust gas and the operations requested to calculate the
pollutant emissions in steady-state and transient test cycles.BS ISO 8178-1 pdf download.