ISO/TS 17536-5:2018

TECHNICAL ISO/TS
SPECIFICATION 17536-5
First edition
2018-09
Road Vehicles — Aerosol separator
performance test for internal
combustion engines —
Part 5:
Engine fractional efficiency test
method and upstream distribution
sampling method
Véhicules Routiers — Norme d'essai de performance des filtres des
circuits fermés de ré-aspiration des gaz de carter moteur —
Partie 5: Méthode d'essai d'efficacité fractionnaire moteur et méthode
d'échantillonnage de la distribution amont
Reference number
©
ISO 2018
© ISO 2018
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ii © ISO 2018 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms, definitions, and abbreviated terms . 1
3.1 Terms and definitions . 1
3.2 Abbreviated terms . 1
4 Measurement accuracy . 2
5 Test materials and test conditions . 2
5.1 Test oil and aerosol. 2
5.2 Absolute filter, wall flow trap and leakage . 2
5.3 Test conditions . 2
5.4 Aerosol Sampling System . 2
5.5 Particle Counter(s) sizing and counting monitor(s). 3
6 Test procedure . 3
6.1 General . 3
6.2 Test equipment . 4
6.3 Concentration Limit of the Particle Counter . 5
6.4 100 % Efficiency Test and Development of Purge Time . 5
6.5 Correlation Test . 5
6.6 Particle Counter(s) Zero . 5
6.7 Particle Counter(s) Sizing Accuracy . 5
6.8 Summary of Qualification Test Requirements . 5
6.9 Apparatus validation and maintenance . 6
7 Test Procedures . 6
7.1 General . 6
7.2 Fractional Efficiency Test Procedure . 7
7.3 Engine aerosol sampling procedure . 8
8 Calculations and data acceptance criteria for the engine fractional efficiency test.8
8.1 General . 8
8.2 Symbols and Subscripts used in the following equations . 9
8.3 Test Sampling . 9
8.4 Correlation Ratio .10
8.5 Penetration/Fractional efficiency .11
8.6 Efficiency .11
8.7 Data Reduction .11
Annex A (informative) Aerosol separator engine fractional efficiency test report .16
Annex B (normative) Test equipment .18
Annex C (normative) Poisson Statistics .21
Bibliography .23
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
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.org/iso/foreword .html.
This document was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 34,
Propulsion, powertrain and powertrain fluids.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/members .html.
A list of all parts in the ISO 17536 series can be found on the ISO website.
iv © ISO 2018 – All rights reserved

Introduction
Engine crankcase blowby is composed of combustion exhaust gases which have escaped to the
crankcase via piston ring seals and lube oil aerosols generated by thermal and mechanical action
within the engine. These gases are vented from the crankcase to prevent a build-up of high pressure.
The constituents of vented engine blowby gases are recognized as an undesirable contaminant and
technology for their containment is therefore evolving.
The device used to separate oil aerosols from the blowby typically releases cleaned gases to atmosphere
or into the air inlet prior to the engine or turbo compressor (if present). The latter has led to the
requirement for a pressure control device to isolate the engine from turbo inlet suction.
It is the purpose of this document to either define standardized and repeatable test procedures for the
evaluation of blowby oil aerosol separators and filtering devices using this engine fractional efficiency
test method and/or determining the size distribution of the blowby aerosol from the engine.
TECHNICAL SPECIFICATION ISO/TS 17536-5:2018(E)
Road Vehicles — Aerosol separator performance test for
internal combustion engines —
Part 5:
Engine fractional efficiency test method and upstream
distribution sampling method
1 Scope
This document defines standardized and repeatable test procedures by using internal combustion
engines for the evaluation of blowby oil aerosol, and aerosol separators and filtering devices by
specifying the engine blowby sampling procedure and engine fractional efficiency test in both open
and closed crankcase ventilation systems running at steady state. Due to sampling requirements,
measuring efficiency when there are transient flow conditions is not in scope.
Separator life is not evaluated in this document.
Conformance of a device to legislation is outside of the scope of this document.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 17536-1, Road vehicles — Aerosol separator performance test for internal combustion engines —
Part 1: General
3 Terms, definitions, and abbreviated terms
For the purposes of this document, the terms and definitions given in ISO 17536-1 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http: //www .electropedia .org/
— ISO Online browsing platform: available at https: //www .iso .org/obp
3.1 Terms and definitions
3.1.1
fractional separation efficiency
ability of the separator to remove particles of a specified size expressed as a percentage
3.2 Abbreviated terms
PSL polystyrene latex, referring to commercially available particles of various specific sizes
4 Measurement accuracy
The measurement accuracy of this document shall be in accordance with ISO 17536-1.
5 Test materials and test conditions
5.1 Test oil and aerosol
The engine oil shall be documented for make, type, viscosity, cleanliness, and density.
The aerosol produced by the engine shall be measured using a calibrated particle size measurement
device.
Mass aerosol distribution shall be displayed in Particle Size (μm) versus mass percent less than
stated size.
The test conditions, engine aerosol size distribution, and fractional efficiency shall be documented. See
Annex A, Figures A.1, A.2 and A.3 for a sample test reporting structure.
5.2 Absolute filter, wall flow trap and leakage
The provisions related to the absolute filter (if present), the downstream wall flow trap (if present), and
leakage shall be in accordance with ISO 17536-1.
5.3 Test conditions
Flow rate for efficiency tests shall be recorded in volumetric flow. All engine efficiency tests shall be
documented with actual on-engine blowby temperature, absolute pressure, and humidity.
5.4 Aerosol Sampling System
5.4.1 The design criterion for the sampling system shall be to provide a particle transport of > 95 %
for 3 μm diameter particles from the sample probe inlet within the test duct to the inlet of the particle
counter.
NOTE This can be verified by experimental measurement or by numerical calculation of particle transport
based upon the geometry of the sampling system, the sampling flow rate, and particle deposition associated with
diffusion, sedimentation, turbulent flow, and inertial forces. Aerosol Measurement: [ ] is a possible reference for
developing a good aerosol sampling system.
5.4.2 The use of a sampling system is allowed to optimize particle transport from the inlet probe to the
particle counter. The sampling system shall meet the following criteria:
5.4.2.1 The portion of the sampling line in the duct shall block less than 25 % of the duct cross-
1)
sectional area .
5.4.2.2 Isokinetic sampling (to within +0 to −10 %) shall be maintained on both upstream and
downstream probes for nominal flow rates.
5.4.2.3 Flow through the sampling system shall be measured to within 5 % with volumetric devices
2)
(e.g., orifice plates and variable area flowmeters) .
1) Taken from: ASTM D1099-97 Standard Practice for Sampling Steam pg. 4 [ ].
2) Taken from: ISO 21501-1:2009, Determination of particle size distribution — Single particle light interaction
methods — Part 1: Light scattering aerosol spectrometer [ ].
2 © ISO 2018 – All rights reserved

5.4.2.4 The upstream and downstream sampling systems shall be of equal length and equivalent
geometry.
5.4.2.5 The airflow rate of the upstream and downstream sampling system shall be <20 % of the
system airflow rate. This requirement excludes low flow conditions (i.e. idle or low RPM). The operator
should try and minimize airflow rate of the upstream system as much as possible as pulling too much air
from the system air flow rate could affect separator performance.
5.4.2.6 The auxiliary pump and associated flow control and flow measurement devices of the sampling
lines shall be downstream of secondary probes.
5.4.2.7 Because a correlation test will be used, the operator does not need to provide equal dilution to
both the upstream and downstream samples.
5.4.2.8 All metal tubing should be grounded. The upstream and downstream sample lines are to be
nominally identical in geometry. The use of a short length (50 mm [2 in.] maximum) of straight, flexible,
metal tubing to make the final connection to the aerosol particle counter is acceptable.
5.4.2.9 The inlet nozzles of upstream and downstream sample probes shall be sharp edged and of
appropriate entrance diameter to maintain isokinetic sampling within +0 to −10 % at the test airflow rate.
5.5 Particle Counter(s) sizing and counting monitor(s)
Permissible instruments used to measure the size and concentration of the aerosol shall meet the
following criteria.
a) If you are only measuring upstream particle distribution, the operator shall measure particle
diameters between 0,3 μm and 10 μm particles and group them into at least 4 channels per decade.
b) If the operator is using this technical specification to measure efficiency, an 8-channel particle
counter (or greater) shall be used. The operator shall measure particle diameters between 0,3 μm
and 10 μm as long as 8.7.4.3 is met.
c) At least 90 % of all observed counts shall register between 0,7 μm to 1,3 μm when the particle
counter is challenged with monodisperse 1,0 μm diameter PSL particles.
3)
d) Shall have at least 50 % counting efficiency at 0,3 um .
e) Shall have less than 10 % coincidence loss during the measurement.
f) Shall measure no more than 10 counts per minute over the 0,30 μm to 10 μm range with a HEPA
filter mounted at the inlet of the counter.
g) The particle counter shall be periodically calibrated according to manufacturer specifications.
h) Shall be able to handle the high air temperatures seen by the raw or conditioned blowby gas coming
off an engine.
6 Test procedure
6.1 General
A fractional efficiency test shall be performed on a complete aerosol separator assembly.
3) Taken from ISO 21501-1.
6.2 Test equipment
NOTE The definitions of the following terms related to the test equipment are defined in ISO 17536-1;
upstream particle counter, particle counter calibration, maximum particle concentration and particle counter flow.
6.2.1 If the user is measuring efficiency, the setup arrangement to determine the efficiency is shown
in Annex B, Figure B.1. Use an engine to supply blowby to the crankcase ventilation system. If the user is
only measuring the distribution from an engine, the arrangement is shown in Annex B, Figure B.2.
6.2.2 Use a wall flow trap between the engine and the inlet tube described in ISO 17536-1 to eliminate
any oil flow to the inlet tube.
NOTE The piezometer can be contaminated without the use of the wall flow trap.
6.2.3 Use an inlet piezometer tube conforming to Figure B.3. The cross-section shall be the same as the
aerosol separator inlet.
6.2.4 Use a manometer or other differential pressure measuring device with the specified accuracy.
6.2.5 Orientation of the unit under test shall be as in application.
6.2.6 Use a wall flow trap similar to the one shown in ISO 17536-1 between the unit under test and the
outlet piezometer tube described in 6.2.3 to eliminate any oil flow to the piezometer, if applicable.
6.2.7 Use an outlet piezometer tube conforming to Figure B.3. The cross-section shall be the same as
the aerosol separator outlet. In the case of non-uniform flow conditions caused by special inlet tubes,
special precautions may be required.
6.2.8 Use an air flow rate measuring system having the accuracy described in ISO 17536-1. Use
a system that is capable of holding the RPM and torque described in ISO 17536-1. Make sure that the
isokinetic sampling tubes meet the specs given in 5.4
6.2.9 If an engine is not capable of generating the blowby flow rate requested, use compressed air/
blower/exhauster for inducing air flow through the system, which has adequate flow rate and pressure
characteristics for the separators to be tested. Pulsation of flow rate shall be so low that it is not
measurable by the flow rate measuring system.
6.2.10 If the components downstream of the unit under test and the environment have a pressure drop
greater than 500 Pa, and it is proven that this pressure drop affects the particle size upstream and/or
downstream of the UUT, a blower/exhauster on the downstream of the system shall be used to regulate
the outlet pressure of the unit under test.
6.2.11 Grounding is required for all test apparatus to reduce the effects of static charge and to improve
the consistency of the test results. Grounding of metallic and non-metallic surfaces, housings, transport
tubes, injectors and associated hardware is recommended.
6.2.12 All tubing up to the point of the downstream sampling device (if present) should be insulated, or
heated, or any other method that will keep the blowby gas above the dew point to eliminate condensation
without changing the particle size distribution. If no separator is being tested, the tubing should be
insulated up to the point of the sampling device (in cases where the operator is only measuring the
engine distribution).
NOTE If the temperature of the blowby gas not maintained, the aerosol distribution could shift due to the
presence of water droplets in the airstream.
4 © ISO 2018 – All rights reserved

6.2.13 Tubing should be the shortest length and have as few bends as possible.
6.2.14 The blank duct should be smooth, conductive metal tubing that includes the minimum bends and
area changes required to replace the separator housing and connect the inlet and outlet piezometers in
the same positions as when the device to be tested is installed.
6.3 Concentration Limit of the Particle Counter
6.3.1 To confirm you do not have coincidence error, either use a particle counter that automatically
determines when you have coincidence error, or watch your total counts to make sure they are below the
manufacturer's limit specification.
6.4 100 % Efficiency Test and Development of Purge Time
6.4.1 An initial efficiency test should be performed using a HEPA filter as the test device to ensure that
the test duct and sampling system are capable of providing a > 99 % efficiency measurement. The test
procedures for determination of efficiency given in Clause 8 shall be followed, and the test should be
performed at two engine conditions, idle and a loaded condition.
6.4.2 The computed efficiency values shall meet the requirements specified in 6.8, Table 1.
6.4.3 One parameter affecting the efficiency during the 100 % efficiency test is the purge time. The
purge time is too short if, after switching from the upstream to the downstream line, residual particles
from the upstream sample are counted during the downstream sampling and yield an efficiency of
< 99 %. In this case, the purge time shall be increased and the 100 % efficiency test repeated.
6.5 Correlation Test
6.5.1 A test shall be performed without a test device in place to check the adequacy of the overall duct,
sampling, measurement, and engine.
6.5.2 The test procedures for determination of the correlation ratio given in 8.4 shall be followed.
6.5.3 The correlation ratio for each particle size shall meet the requirements specified in 6.8, Table 1.
6.6 Particle Counter(s) Zero
The zero count of the particle counter(s) shall meet the requirements specified in 6.8, Table 1
6.7 Particle Counter(s) Sizing Accuracy
The sizing accuracy of the particle counter(s) shall be checked by sampling an aerosol containing
monodisperse polystyrene spheres of known size. A relative maximum particle count shall appear in
the parti
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