ISO/DIS 17536-4

DRAFT INTERNATIONAL STANDARD
ISO/DIS 17536-4
ISO/TC 22/SC 34 Secretariat: ANSI
Voting begins on: Voting terminates on:
2019-02-04 2019-04-29
Road Vehicles — Aerosol separator performance test for
internal combustion engines —
Part 4:
Laboratory fractional efficiency test method
ICS: 43.060.20
THIS DOCUMENT IS A DRAFT CIRCULATED
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This document is circulated as received from the committee secretariat.
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Reference number
NATIONAL REGULATIONS.
ISO/DIS 17536-4:2019(E)
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NOTIFICATION OF ANY RELEVANT PATENT
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PROVIDE SUPPORTING DOCUMENTATION. ISO 2019
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ISO/DIS 17536-4:2019(E)
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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 ............................................................................................................................................................................... 2

4 Measurement Accuracy ................................................................................................................................................................................. 2

5 Test Materials and Conditions ................................................................................................................................................................ 2

5.1 Absolute filter, wall flow trap and leakage ...................................................................................................................... 2

5.2 Test temperature ................................................................................................................................................................................... 2

5.3 Test Conditions ....................................................................................................................................................................................... 2

6 Test procedure ........................................................................................................................................................................................................ 2

6.1 General ........................................................................................................................................................................................................... 2

6.2 Test Equipment ....................................................................................................................................................................................... 3

6.3 Aerosol Generator ................................................................................................................................................................................ 3

6.4 Aerosol sampling system ............................................................................................................................................................... 4

6.5 Particle sizing and counting monitor(s) ........................................................................................................................... 5

7 Apparatus Qualification Testing ........................................................................................................................................................... 5

7.1 Test stand verification ...................................................................................................................................................................... 5

7.2 Concentration Limit of the Particle instrument ......................................................................................................... 5

7.3 100% Efficiency Test and Development of Purge Time....................................................................................... 6

7.4 Correlation Test ...................................................................................................................................................................................... 6

7.5 Test Duct Air Leakage Test ............................................................................................................................................................ 6

7.6 Apparatus Maintenance .................................................................................................................................................................. 6

8 Fractional Efficiency Test ............................................................................................................................................................................. 7

8.1 General ........................................................................................................................................................................................................... 7

8.1.1 New state (if possible) ................................................................................................................................................ 7

8.1.2 Conditioned state per ISO 17536-2 ................................................................................................................. 7

8.2 Method ........................................................................................................................................................................................................... 7

8.3 Calculations ................................................................................................................................................................................................ 7

8.4 Correlation and tare ........................................................................................................................................................................... 7

8.5 Fractional efficiency Test................................................................................................................................................................ 7

9 Calculations and data acceptance criteria ................................................................................................................................. 8

9.1 Symbols used in following equations .................................................................................................................................. 8

9.2 Symbols ......................................................................................................................................................................................................... 8

9.3 Subscripts used in the following equations ................................................................................................................... 9

9.4 Average used in the following equations .......................................................................................................................... 9

9.5 Test Sampling ........................................................................................................................................................................................... 9

9.6 Correlation Ratio ................................................................................................................................................................................11

9.7 Penetration / Fractional efficiency .....................................................................................................................................11

9.8 Efficiency ...................................................................................................................................................................................................12

9.9 Data Reduction .....................................................................................................................................................................................12

Annex A (normative) Poisson Statistics .........................................................................................................................................................19

Annex B (informative) Aerosol separator laboratory fractional efficiency test report ................................21

Annex C (normative) Test Equipment ..............................................................................................................................................................23

Bibliography .............................................................................................................................................................................................................................25

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This document was prepared by Technical Committee [or Project Committee] ISO/TC [or ISO/PC] ###,

This second/third/… edition cancels and replaces the first/second/… edition (ISO #####:####), which

Engine crankcase blow-by 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 shall be 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

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.

NOTE It is the purpose of this part of the ISO 17536 document to define standardized and repeatable

test procedures for the evaluation of blowby oil aerosol separators and filtering devices using this laboratory

This part of ISO 17536 defines standardized and repeatable test procedures for the evaluation of blowby

oil aerosol separators and filtering devices and specifies laboratory fractional separation efficiency in

The conditioned portion of this test only applies to filters that can meet the dP stability requirements

Conformance of a device to legislation is outside of the scope of this standard and the appropriate

The following referenced documents are indispensable for the application of this document. For dated

references, only the edition cited applies. For undated references, the latest edition of the referenced

ISO 17536-1, Road vehicles — Aerosol separator performance test for internal combustion engines —

ISO 17536-2, Road vehicles – Aerosol separator performance test for internal combustion engines -- Part 2:

For the purposes of this document, the terms and definitions given in ISO 17536-1 and the following apply.

The ability of the separator to remove particles of a specified size expressed as a percentage

NOTE Recommended particle instruments are LSAS's, as per Reference [3] or other instruments

PSL polystyrene latex, referring to commercially available particles of various specific sizes

The measurement accuracy of this part of ISO 17536 shall be in accordance with ISO 17536-1, Clause 3.

The provisions related to the absolute filter (if present), the downstream wall flow trap (if present) and

The volume directly outside of the UUT and internal temperature of the efficiency test shall be either:

a. Flow rate: Air flow rate and mass oil flow are specified by the customer or by the test requestor.

b. Clean condition: The user should run a clean pressure loss test as specified in 17536-2. The clean

pressure loss test is conducted before any oil aerosol is allowed to enter the unit under test (UUT)

c. If gravimetric efficiency (per 17536-2) and fractional efficiency tests are being performed

simultaneously, once the oil flow has been started for a test the air flow and oil flow shall not be

d. The conditioned fractional efficiency is measured after reaching the condition specified in 17536-2.

NOTE Aerosol size distribution is not specified in this document, however two possible distributions are as

follows. D50: 0.85 - 0.9 µm (Same as TS17536-2) or to the customer’s specification.

Performance tests shall be performed on a complete aerosol separator assembly. The tests shall

consist of a fractional efficiency test and a conditioned fractional efficiency test (when applicable). If a

gravimetric efficiency test, conditioned gravimetric efficiency test, pressure loss, crankcase pressure

control test (when pressure regulator is present), or a drain interval test (when applicable) will be

NOTE The definitions of the following terms related to the test equipment are defined in ISO 17536-1,;

upstream particle instrument, particle instrument calibration, maximum particle concentration and particle

6.2.1 The duct material shall be electrically conductive and electrically grounded (metal duct), have

a smooth interior finish, and be sufficiently rigid to maintain its shape at the operating pressures. The

6.2.2 Typical arrangements to determine the fractional efficiency are shown in Annex C.

6.2.3 Use an aerosol generator which is capable of dosing oil mist over the range of sizes required as

6.2.4 An upstream wall flow trap should be used between the oil mist generator and the inlet duct to

eliminate any oil wall flow to the inlet duct. Use a wall flow trap conforming to ISO 17536-1.

6.2.5 Use an inlet piezometer tube conforming to ISO 17536-1. The cross-section shall be the same

as the aerosol separator inlet. In the case of non-uniform flow conditions caused by special inlet ducts,

6.2.6 Use a manometer or other differential pressure measuring device with the specified accuracy

6.2.7 A downstream wall flow trap should be used between the unit under test and the outlet

piezometer tube described in 6.2.5 (if present) to eliminate any oil wall flow. Use a wall flow trap

6.2.8 Use an outlet duct conforming to ISO 17536-1. The cross-section shall be the same as the aerosol

separator outlet. In the case of non-uniform flow conditions caused by special inlet ducts, special

6.2.9 Use an air flow rate measuring system having the accuracy described in ISO 17536-1. . The device

needs to be calibrated to the environmental conditions inside the inlet duct at the test conditions used.

6.2.10 Use an air flow rate control system with a refresh rate greater than or equal to 2 hertz capable of

6.2.11 Use compressed air/blower/exhauster for controlling air flow through the system, which has

adequate flow rate and pressure characteristics for the oil separators to be tested.

6.2.12 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

6.3.1 Aerosol concentration shall be measured by particle counting. The concentration shall be

6.3.2 The test oil shall be documented for surface tension, density and viscosity. The temperature of

the aerosol flow shall be measured at the filtration system inlet. Run test at conditions specified in 5.3

The design criterion for the sampling system should be to provide a particle transport of >95% for

3μm diameter particles from the sample probe inlet within the test duct to the inlet of the particle

NOTE This shall 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, as described in Reference [1]

6.4.1 The use of a sampling system is allowed to optimize particle transport from the inlet probe to the

6.4.1.1 The portion of the sampling line in the duct shall block less than 25% of the duct cross-

6.4.1.2 Isokinetic sampling (to within +0 to -10%) shall be maintained on both upstream and

6.4.1.3 Flow through the sampling system shall be measured to within 5% with volumetric devices

NOTE Sampling air flow should be considered in total flow rate (e.g. 3lpm sampling at 30lpm rated flow)

6.4.1.4 Combined particle losses in the system should be < 5% for 3 μm diameter particles, based on

6.4.1.5 The upstream and downstream sampling systems shall be of equal length and equivalent

6.4.1.6 Where the upstream sampling system flow rate is greater or equal to 20% of the system air

flow rate, compensation of the downstream particle count system flow rate shall account for the flow

6.4.1.7 Where the downstream sampling system flow rate is greater than or equal to 20% of the system

air flow rate, compensation of the downstream particle count system flow rate shall account for the flow

6.4.1.8 Position of auxiliary components (i.e. wall flow trap) shall not change PSD, will need to verify

6.4.1.9 User shall verify the dilution ratio and ensure that the dilution does not change the particle

6.4.1.10 Ground all metal tubing and/or use grounded plastic tubing (carbon or imbedded wire). The

upstream and downstream sample lines are to be nominally identical in geometry and shall use the

6.4.1.11 The inlet nozzles of upstream and downstream sample probes shall be sharp edged (< 15

degree included angle) and of appropriate entrance diameter to maintain isokinetic sampling within +0

Permissible instruments used to measure the size and concentration of the aerosol shall meet the

6.5.1 Shall measure particle diameters between 0.3 and 5 um particles and group them into at least 8

6.5.2 At least 90% of all observed counts shall register between 0.7 to 1.3 μm when the particle

6.5.5 Shall measure no more than 10 counts per minute over the 0.30 to 5 μm range with a HEPA filter

6.5.6 The particle instrument shall be periodically calibrated according to manufacturer specifications.

NOTE Particle counters often are calibrated for dust, which may give erroneous results when used for this test.

7.1.1 Apparatus qualification tests shall verify quantitatively that the test rig and sampling procedures

are capable of providing reliable particle size efficiency measurements. The tests shall be performed in

Particle instrument Zero Count Check: Based on HEPA filter attached <10 counts per minute over the 0.30 to

Particle instrument Sizing Accuracy Check: Based on sampling of aero- Relative maximum shall appear in the

7.2.1 A series of initial efficiency tests shall be performed over oil aerosol concentrations to determine

a total concentration level for the PSE tests that does not overload the particle instrument(s). The lowest

total concentration level shall be less than 1% of the instrument’s stated total concentration limit.

The tests shall be performed following the procedures of 8.1 through 8.6 on a device using a range of

upstream aerosol concentrations. The tests shall be performed 10%, 50%, 100% and 200% of rated flow.

7.2.2 The aerosol for these tests shall be generated using the same system and procedures as described

7.2.3 The tests shall be performed over a sufficient range of total challenge concentrations to

demonstrate that the particle instrument(s) is not overloaded at the intended test concentration.

7.3.1 An initial efficiency test shall 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 PSE given in Clause 9 shall be followed, and the test shall be performed

7.3.3 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.

7.4.1 A test shall be performed without a test device in place to check the adequacy of the overall duct,

7.4.2 The test procedures, given in 9.6, for determination of the correlation ratio shall be followed.

7.4.3 The correlation ratio for each particle size shall meet the requirements specified in Table 6.

7.5.1 Air leakage from the test duct shall not exceed 1% of the airflow rate of test filter.

7.5.2 The leak rate of the test duct shall be evaluated by a method similar to that delineated in ANSI/

ASME N510. The test duct shall be sealed immediately upstream of the aerosol injection location.