ISO/TS 17536-2:2017

TECHNICAL ISO/TS
SPECIFICATION 17536-2
First edition
2017-10
Road vehicles — Aerosol separator
performance test for internal
combustion engines —
Part 2:
Laboratory test method
Véhicules routiers — Essai de performance du séparateur d'aérosols
pour les moteurs à combustion interne —
Partie 2: Méthode d'essai de laboratoire
Reference number
©
ISO 2017
© ISO 2017, Published in Switzerland
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ii © ISO 2017 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Measurement accuracy . 1
5 Test materials and test conditions . 2
5.1 Test oil . 2
5.2 Absolute filter, wall flow trap and leakage . 2
5.3 Standard conditions . 2
5.4 Test temperature . 2
5.4.1 Efficiency tests . 2
5.4.2 Differential pressure, pressure loss and crankcase pressure control tests . 2
6 Test procedure . 2
6.1 General . 2
6.2 Test equipment . 2
6.3 Pressure loss test . 4
6.4 Gravimetric efficiency test . 4
6.5 Conditioning of the separation device before a conditioned gravimetric efficiency test . 6
6.6 Conditioned gravimetric efficiency test . 6
6.7 Crankcase pressure control test . 7
6.8 Drain interval test . 7
Annex A (informative) Inlet geometry for equal oil flow challenge .10
Annex B (normative) Aerosol distribution by mass .11
Annex C (informative) Aerosol separator laboratory gravimetric test report .13
Annex D (normative) Test equipment .18
Annex E (normative) Differential pressure and pressure loss corrections to standard conditions 22
Bibliography .24
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
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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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URL: www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 34,
Propulsion, powertrain and powertrain fluids.
A list of all parts in the ISO 17536 series can be found on the ISO website.
iv © ISO 2017 – All rights reserved

Introduction
The 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 the
atmosphere or alternatively returns the cleaned product to the combustion process by feeding into the
engine air intake prior to the turbo compressor (if present). The latter has led to the requirement for a
pressure control device to isolate the engine crankcase from air intake pressure.
It is the purpose of this document to define standardized and repeatable test procedures for the evaluation
of blowby oil aerosol separators and filtering devices using this laboratory gravimetric test method.
TECHNICAL SPECIFICATION ISO/TS 17536-2:2017(E)
Road vehicles — Aerosol separator performance test for
internal combustion engines —
Part 2:
Laboratory test method
1 Scope
This document defines standardized and repeatable test procedures for the evaluation of blowby oil
aerosol separators and filtering devices and specifies laboratory gravimetric separation efficiency and
system pressure tests in both open and closed crankcase ventilation systems. This document has a
limitation of 0 % to 99 % for aerosol gravimetric efficiency.
NOTE Gravimetric efficiencies >99 % may be difficult to measure due to long test durations and absolute
filter weight measurements.
Filter life is not evaluated in this document.
This test method only applies to devices that have a defined tubular inlet, outlet and drain that can be
connected to the test equipment. For devices that lack such connections, for example, one that is built
into a valve cover, see Annex A.
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 17536-1:2015, Road vehicles — Aerosol separator performance test for internal combustion engines —
Part 1: General
3 Terms and definitions
For the purposes of this document, the following terms and definitions 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 http://www.iso.org/obp
3.1
standard flow
flow rate corrected to standard conditions
Note 1 to entry: See 5.3 for details.
4 Measurement accuracy
The measurement accuracy of this document shall be in accordance with ISO 17536-1:2015, Clause 3.
5 Test materials and test conditions
5.1 Test oil
The test oil to be used shall be an oil of such appropriate viscosity and surface tension that the particle
size of 50 % cumulative mass of the generated aerosol exhibits more than 0,85 μm and less than
0,90 μm. The test oil shall meet the aerosol distribution by mass given in Annex B. The challenge aerosol
size distribution shall be plotted in Figure C.1.
5.2 Absolute filter, wall flow trap and leakage
The provisions related to the absolute filter, the downstream wall flow trap and leakage shall be in
accordance with ISO 17536-1:2015, Clause 4.
5.3 Standard conditions
The standard condition for temperature, humidity and pressure is 20 °C, 0 % RH and 101,3 kPa
(1 013 mbar). Airflow differential pressure, inlet and outlet pressure and pressure loss shall be
corrected to that standard condition.
5.4 Test temperature
5.4.1 Efficiency tests
The volume directly outside of the UUT and internal temperature of the efficiency test shall be either:
Condition A: 80 °C ± 3 °C
Condition B: 23 °C ± 5 °C
The condition that is run shall be documented in the test report (see Table C.1).
5.4.2 Differential pressure, pressure loss and crankcase pressure control tests
The flow rate for pressure loss and crankcase pressure control tests shall be corrected to standard
flow. The pressure loss and crankcase pressure control tests shall be conducted with air entering the
aerosol separator at a temperature of 23 °C ± 5 °C.
6 Test procedure
6.1 General
Performance tests shall be performed on a complete aerosol separator assembly. The tests shall consist
of a pressure loss test, gravimetric efficiency test, conditioned gravimetric efficiency test, crankcase
pressure control test (when a pressure regulator is present) and drain interval test (when applicable).
6.2 Test equipment
NOTE The definitions of the following terms related to the test equipment are defined in ISO 17536-1:2015,
Clause 2: upstream particle counter, particle counter calibration, maximum particle concentration and particle
counter flow.
6.2.1 Typical arrangements to determine the differential pressure or pressure loss to air flow, efficiency
and crankcase pressure control are shown in Annex D.
Use an aerosol generator which is capable of dosing oil mist over the range of delivery rates required
according to the customers' specification.
2 © ISO 2017 – All rights reserved

The aerosol generator shall be validated as follows.
— Fill the aerosol generator to a pre-determined level.
— Simultaneously start the aerosol generator and timer.
— At a time interval relative to a mass oil flow of >1 g, determine the amount of aerosol dispersed and
particle size distribution. Continue mass oil flow determinations of the aerosol until the desired oil
flow deviates by <5 % and shall be >30 min. Continue feeding aerosol until the particle distribution
does not meet the Annex B specification (to understand time capability to deliver a distribution as
specified in Annex B).
— Adjust the aerosol generator until the average delivery rate is within ±5 % of the desired rate and
deviation in the delivery rate from the average is not more than ±5 % for the entire designated test
duration.
— After verifying the delivery rate, verify the aerosol delivered from the aerosol generator for the
entire test duration is within the Annex B specifications.
6.2.2 An upstream wall flow trap should be used between the oil mist generator and the inlet tube
to eliminate any oil wall flow to the inlet tube. Use a wall flow trap conforming to ISO 17536-1:2015,
Annex I.
6.2.3 Use an inlet piezometer tube conforming to ISO 17536-1:2015, Figure B.2. The cross-section
shall be the same as the aerosol separator inlet. In the case of non-uniform flow conditions caused by
special inlet tubes, special precautions may be required.
6.2.4 Use a manometer or other differential pressure measuring device with the specified accuracy
described in ISO 17536-1:2015, Clause 3.
6.2.5 Setup test with no UUT present, e.g. straight pipe.
6.2.6 A downstream wall flow trap should be used between the unit under test and the outlet
piezometer tube described in 6.2.3 to eliminate any oil wall flow. Use a wall flow trap conforming to
ISO 17536-1:2015, Annex I.
6.2.7 Use an outlet tube conforming to ISO 17536-1:2015, Figure B.2. 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 17536-1:2015,
Clause 3. The flow rate for differential pressure and crankcase pressure control tests shall be standard
flow, which is the volume flow rate corrected to standard conditions, as specified in 5.3.
6.2.9 Use an air flow rate control system with a refresh rate greater than 2 Hz capable of maintaining
the indicated flow rate to within 5 % of the selected value at a minimum data record frequency of 2 Hz
during a steady-state and variable air flow operation.
6.2.10 Use a compressed air/blower/exhauster for controlling the air flow through the system, which
has adequate flow rate and pressure characteristics for the oil separators to be tested.
6.2.11 If the unit under test has a pressure regulator or bypass, the use of a blower/exhauster on the
downstream of the system can be used to regulate the pressure on the outlet of the unit under test.
Devices with pressure regulators shall have air pushed through the inlet because the pressure regulator
device regulates the amount of negative vacuum allowed on the system.
6.2.12 Grounding is required for all test apparatus to reduce the effects of static charges 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.
6.3 Pressure loss test
6.3.1 The purpose of this test is to determine the pressure loss across the unit under test which will
result when air is passed through under predetermined conditions. Airflow differential pressure is
measured with a clean aerosol separator at least four equally spaced air flows or agreed upon between
the customer and supplier.
6.3.2 Set up the UUT as shown in ISO 17536-1:2015, Figure B.1, Figure D.1 or Figure D.3. Seal all joints
to prevent air leaks. Connect the piezometer tubes to the inlet and outlet of the unit under test. The
piezometer tube shall be sized to the size of the inlet and outlet of the UUT.
Care should be taken to understand the product components that may affect the flow path during a
pressure loss test, e.g. pressure regulators.
6.3.3 Record the inlet temperature, barometric pressure and relative humidity.
6.3.4 Measure and record the differential pressure and upstream absolute pressure of the unit under
test versus the air flow rate at a minimum of four equally spaced air flows or flow rates agreed upon
between the customer and supplier.
6.3.5 Record the inlet temperature, barometric pressure and relative humidity.
6.3.6 Recorded differential pressure readings shall be corrected to standard conditions in accordance
with Annex E. See Formulae (E.4) and (E.5).
6.3.7 For pressure loss determination, use the formula given in ISO 17536-1:2015, Annex A.
6.3.8 Plot the pressure loss as shown in Figure C.2 or equivalent.
6.4 Gravimetric efficiency test
6.4.1 The purpose of the gravimetric efficiency test is to determine the gravimetric separation
efficiency of a device in two conditions:
a) new state;
b) conditioned state, as specified in 6.5.
The test duration for a gravimetric efficiency test shall be a minimum of 30 min and the minimum mass
gained on the absolute filter shall be 0,1 g. Additional time may be needed to achieve the absolute filter
weight gain requirement. The weight changes of the component parts and the absolute filter during the
test duration are used to calculate the new and conditioned state gravimetric efficiency.
High efficiency separators shall not exceed 3 h for 6.4.1, a) as the new state is no longer maintained. For
such separators, 6.5 and 6.6 shall be performed to complete an efficiency evaluation on the product and
shall meet the above minimum requirements of 30 min and 0,1 g on the absolute filter.
NOTE The higher efficiency separators can require additional time to achieve the specified absolute filter
weight gain requirement.
4 © ISO 2017 – All rights reserved

6.4.2 The mass oil flow is agreed upon by the user and manufacturer.
Care should be taken to understand that mass oil flow may affect the challenge aerosol size distribution.
6.4.3 Weigh and record the unit under test.
6.4.4 Weigh and record the drainage vessel (if present).
6.4.5 Weigh the absolute filter as specified in ISO 17536-1:2015, 4.1.2 and record the mass before
assembly within the absolute filter housing.
6.4.6 Weigh the downstream wall flow trap of the unit under test as specified in ISO 17536-1:2015, 4.2.1.
6.4.7 Setup the test stand as shown in Figure D.2 or Figure D.4 for all aerosol separators. Seal all joints
to prevent air leakage. The orientation of the unit under test shall be as in application.
Care should be taken to understand the product components that may affect the flow path during a
pressure loss test, e.g. pressure regulators.
6.4.8 Record the UUT external air temperature, pressure and relative humidity.
6.4.9 Start the air flow through the test stand as specified in 5.4.1 and stabilize at the test flow as
specified in 6.2.8. Record the differential pressure.
6.4.10 Set the feed rate to the pre-determined oil flow. Start the aerosol generator.
6.4.11 The differential pressure shall be compensated for the increased differential pressure that the
tubing and downstream wall flow trap between the unit under test and the piezometer introduces,
since the downstream wall flow trap will be in this area. The downstream wall flow trap is present to
protect the downstream piezometer from contamination of liquid oil wall flow. The pressure loss of the
downstream wall flow trap shall be subtracted from the overall pressure loss.
6.4.12 Every 10 min, record the differen
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