ISO 5011:2020

Inlet air cleaning equipment for internal combustion engines and compressors — Performance testing

This document establishes and specifies uniform test procedures, conditions, equipment and a performance report to permit the direct laboratory performance comparison of air cleaners. The basic performance characteristics of greatest interest are air flow restriction or differential pressure, dust collection efficiency, dust capacity and oil carry-over on oil bath air cleaners. This test code therefore deals with the measurement of these parameters. This document is applicable to air cleaners used on internal combustion engines and compressors generally used in automotive and industrial applications.

Séparateurs aérauliques placés à l'entrée des moteurs à combustion interne et des compresseurs — Détermination des performances

General Information

• Status: Published
• Publication Date: 10-Sep-2020
• ICS: 43.060.20 - Pressure charging and air/exhaust gas ducting systems
• Technical Committee: ISO/TC 22/SC 34 - Propulsion, powertrain and powertrain fluids
• Drafting Committee: ISO/TC 22/SC 34/WG 3 - Air filters
• Current Stage: 9092 - International Standard to be revised
• Completion Date: 27-Feb-2023

Relations

• Revises: ISO 5011:2014 - Inlet air cleaning equipment for internal combustion engines and compressors — Performance testing
• Effective Date: 10-Dec-2016
• Revises: ISO 5011:2014/Amd 1:2018 - Inlet air cleaning equipment for internal combustion engines and compressors — Performance testing — Amendment 1
• Effective Date: 23-Apr-2020

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 5011
Fourth edition
2020-09
Inlet air cleaning equipment for
internal combustion engines and
compressors — Performance testing
Séparateurs aérauliques placés à l'entrée des moteurs à combustion
interne et des compresseurs — Détermination des performances
Reference number
ISO 5011:2020(E)
©
ISO 2020

---------------------- Page: 1 ----------------------
ISO 5011:2020(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 5011:2020(E)

Contents Page
Foreword .v
1 Scope . 1
2 Normative references . 1
3 Terms, definitions and symbols . 1
3.1 Terms and definitions . 1
3.2 Symbols . 3
4 Measurement accuracy and standard conditions . 4
4.1 Measurement accuracy and precision . 4
4.2 Standard conditions . 4
5 Test materials and test conditions . 4
5.1 Test dust . 4
5.1.1 Grade . 4
5.1.2 Preparation . 4
5.2 Test oil for oil bath air cleaners . 5
5.3 Absolute filter materials . 5
5.3.1 Filter media . 5
5.3.2 Validation of absolute filter media efficiency, E . 5
a
5.4 Absolute filter mass . 5
5.5 Temperature and humidity . 6
6 Test procedure for dry-type air cleaners for automotive applications .6
6.1 General . 6
6.2 Test equipment . 6
6.3 Restriction and differential pressure test . 8
6.4 Efficiency test . 8
6.4.1 Purpose . 8
6.4.2 Types . 8
6.4.3 Test procedure — Absolute filter method . 9
6.4.4 Test procedure — Direct weighing method .10
6.5 Capacity test .10
6.6 Filter element pressure collapse test.11
6.7 Variable air flow test .11
6.8 Presentation of data .12
7 Test procedure for dry-type air cleaners for industrial applications .12
7.1 General .12
7.2 Test equipment .12
7.3 Restriction and differential pressure test .13
7.4 Initial efficiency test procedure — Absolute filter method .13
7.5 Full-life efficiency and capacity test.14
7.5.1 Air cleaner dust capacity .14
7.5.2 Test procedure — Absolute filter method .14
7.5.3 Test procedure — Direct weighing method .16
7.6 Presentation of data .16
7.7 Scavenged air cleaner performance test .16
7.7.1 General.16
7.7.2 Additional equipment . .17
7.7.3 Restriction and differential pressure test .17
7.7.4 Full-life efficiency and capacity test .17
7.7.5 Presentation of data .18
7.8 Precleaner performance test .18
7.8.1 Precleaner dust removal .18
7.8.2 Precleaner efficiency .19
7.8.3 Presentation of data .19
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ISO 5011:2020(E)

7.9 Secondary element test procedure .19
7.9.1 General.19
7.9.2 Specific efficiency test .19
7.9.3 Expression of results .20
8 Test procedure for industrial applications of oil bath air cleaners.20
8.1 General .20
8.2 Test equipment and conditions .20
8.3 Restriction and differential pressure test .21
8.4 Oil carry-over test .21
8.5 Full life efficiency and capacity test .21
8.6 Recovery test .22
8.7 Presentation of data .22
Annex A (normative) Explanation of restriction, differential pressure and pressure loss of
an air cleaner .23
Annex B (normative) Test equipment .25
Annex C (informative) Report sheet on performance testing of air cleaner equipment
according to ISO 5011 — Automotive application .35
Annex D (informative) Report sheet on performance testing of air cleaner equipment
according to ISO 5011 — Industrial application .36
Annex E (informative) Presentation of results — Air cleaner restriction/differential
pressure versus flow.38
Annex F (informative) Presentation of results — Air cleaner capacity .39
Annex G (normative) Airflow and resistance corrections to standard conditions .40
Annex H (normative) Penetration sensitivity .42
Bibliography .50
iv © ISO 2020 – All rights reserved

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ISO 5011:2020(E)

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
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see 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.
This fourth edition cancels and replaces the third edition (ISO 5011:2014), which has been technically
revised. It also incorporates the Amendment ISO 5011:2014/Amd.1:2018. The main changes compared
to the previous edition are as follows:
— added a validation procedure for verifying efficiency measurements;
— revised recommended ISO dust injector table;
— added formula for precleaner efficiency method;
— removed requirement for secondary element collapse test;
— added Annex H (Penetration sensitivity);
— added a new dust injector.
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.
© ISO 2020 – All rights reserved v

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INTERNATIONAL STANDARD ISO 5011:2020(E)
Inlet air cleaning equipment for internal combustion
engines and compressors — Performance testing
1 Scope
This document establishes and specifies uniform test procedures, conditions, equipment and a
performance report to permit the direct laboratory performance comparison of air cleaners.
The basic performance characteristics of greatest interest are air flow restriction or differential
pressure, dust collection efficiency, dust capacity and oil carry-over on oil bath air cleaners. This test
code therefore deals with the measurement of these parameters.
This document is applicable to air cleaners used on internal combustion engines and compressors
generally used in automotive and industrial applications.
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 5167-1, Measurement of fluid flow by means of pressure differential devices inserted in circular cross-
section conduits running full — Part 1: General principles and requirements
ISO 12103-1, Road vehicles — Test contaminants for filter evaluation — Part 1: Arizona test dust
3 Terms, definitions and symbols
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:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1 Terms and definitions
3.1.1
air filter
air cleaner
device which removes particles suspended in the intake air as it is drawn into the engine
3.1.2
filter element
replaceable part of the air filter (3.1.1), consisting of the filter material and carrying frame
3.1.3
secondary element
air cleaner (3.1.1) element fitted downstream of the primary element for the purpose of providing the
engine with protection against dust in the event of
a) certain types of primary element failure, or
b) dust being present during the removal of the primary element for servicing
© ISO 2020 – All rights reserved 1

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ISO 5011:2020(E)

3.1.4
unit under test
either a single air cleaner (3.1.1) element or a complete air cleaner assembly
3.1.5
single-stage air cleaner
air cleaner (3.1.1) which does not incorporate a separate precleaner (3.1.7)
3.1.6
multistage air cleaner
air cleaner (3.1.1) consisting of two or more stages, the first usually being a precleaner (3.1.7), followed
by one or more filter elements (3.1.2)
Note 1 to entry: If two elements are used, the first is called the primary element and the second one is called the
secondary element (3.1.3).
3.1.7
precleaner
device usually using inertial or centrifugal means to remove a portion of the test dust prior to reaching
the filter element (3.1.2)
3.1.8
test air flow
measure of the quantity of air drawn through the air cleaner (3.1.1) outlet per unit time
Note 1 to entry: The flow rate is expressed in cubic metres per minute corrected to standard conditions.
3.1.9
rated air flow
flow rate specified by the user or manufacturer
Note 1 to entry: It may be used as the test air flow (3.1.8).
3.1.10
scavenged air flow
measure of the quantity of air used to remove the collected dust from a precleaner (3.1.7)
Note 1 to entry: It is expressed as a percentage of the test air flow (3.1.8).
3.1.11
static pressure
pressure in a duct, at the observed air flow rate, measured by connecting a pressure gauge to a hole or
holes drilled in the wall of the duct
Note 1 to entry: In the tests specified in this document, a static pressure is measured by a manometer (usually a
liquid manometer) as a negative pressure difference against the atmospheric pressure and in the formula this is
treated as a positive value.
3.1.12
restriction
static pressure (3.1.11) measured immediately downstream of the unit under test (3.1.4)
3.1.13
differential pressure
difference in static pressure (3.1.11) measured immediately upstream and downstream of the unit under
test (3.1.4)
2 © ISO 2020 – All rights reserved

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ISO 5011:2020(E)

3.1.14
pressure loss
measure of the loss of energy caused by an air cleaner (3.1.1) at the observed air flow rate
Note 1 to entry: It is expressed as the differential pressure (3.1.13) corrected for any difference in the dynamic
head at the measuring points.
Note 2 to entry: For further information, see Annex A.
3.1.15
absolute filter
filter downstream of the unit under test (3.1.4) that retains the contaminant passed by the unit under test
3.1.16
efficiency
ability of the air cleaner (3.1.1) or the unit to remove contaminant mass under specified test conditions
3.1.17
capacity
quantity of contaminant removed by the unit under test (3.1.4) in producing specified terminal
conditions
3.1.18
oil carry-over
appearance of oil at the cleaner outlet
3.1.19
test terminal condition
condition, relating to an air cleaner (3.1.1), the occurrence of which signifies the end of the test
Note 1 to entry: A test terminal condition may be, for example, any one of the following: the restriction (3.1.12)
or the differential pressure (3.1.13) reaches a specified or agreed terminal value; the dust-removing efficiency
(3.1.16) or some other performance parameter falls to a specified or agreed value; oil carry-over (3.1.18) occurs;
a dust pot becomes filled.
3.1.20
automotive application
air cleaner (3.1.1) generally used for internal combustion engines in passenger cars
3.1.21
industrial application
air cleaner (3.1.1) generally used for internal combustion engines in heavy-duty trucks, construction
equipment and agricultural tractors
3.2 Symbols
The following applied units, according to ISO 80000-1, are used.
Name Symbol Unit
3
Density ρ kg/m
Differential pressure Δp Pa
d
Mass m g
Mass flow rate q kg/min
m
Pressure p Pa
Pressure loss Δp Pa
l
Restriction Δp Pa
r
Temperature T °C
Time t s
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ISO 5011:2020(E)

Name Symbol Unit
Velocity v m/s
3
Volume flow rate q m /min
V
4 Measurement accuracy and standard conditions
4.1 Measurement accuracy and precision
Measure the air flow rate to within ±2 % of the actual value, except for the variable air flow test when
accuracy may be ±2 % of the maximum value of the cyclic flow rate through the cleaner.
Measure the differential pressure and restriction to within 25 Pa for pressure readings up to 10 kPa,
within 1 % of reading for higher pressures.
Measure the temperature to within 0,5 °C of the actual value.
Measure the mass to within 0,1 g with the exception of absolute filter mass to be measured at 0,01 g and
with the exception of the feeder mass to be measured at 1 %.
Measure the relative humidity (RH) with an accuracy of ±2 % RH.
Measure the barometric pressure to within 0,3 kPa.
The measurement equipment shall be calibrated at regular intervals to ensure the required accuracy.
Follow Annex H to determine the reporting precision of your efficiency measurement.
4.2 Standard conditions
All airflow measurements shall be corrected to a standard condition of 20 °C at 101,3 kPa.
See Annex G.
5 Test materials and test conditions
5.1 Test dust
5.1.1 Grade
The test dust to be used shall be ISO 12103-1, A.2 (ISO fine) or ISO 12103-1, A.4 (ISO coarse), subject
to agreement between the filter manufacturer and client. The chemical analysis and the particle size
distribution shall conform to ISO 12103-1.
In the absence of an agreement on the dust:
— for single-stage filters, use ISO fine test dust, and
— for multistage filters, use ISO coarse test dust.
5.1.2 Preparation
Before using the test dust, a quantity sufficient to cover the test requirements shall be mixed to
ensure that no stratification / clumping has occurred. The test dust shall then be allowed to become
acclimatised to a constant mass under the prevailing test conditions.
NOTE To ensure a constant rate of dust feed with some dust feeders, it can be found necessary to heat the
dust prior to being acclimated to the environment.
4 © ISO 2020 – All rights reserved

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ISO 5011:2020(E)

5.2 Test oil for oil bath air cleaners
The oil used for testing oil bath air cleaners shall be that specified by the filter manufacturer and agreed
by the user for use at the appropriate ambient temperature. If an oil is not specified, the test oil shall be
a heavy-duty oil and the viscosity at the temperature of the test shall be adjusted as follows:
2
— 85 mm /s for oil carry-over and restriction/differential pressure tests;
2
— 330 mm /s for efficiency and capacity tests, including an oil carry-over test after the capacity test.
5.3 Absolute filter materials
5.3.1 Filter media
The absolute filter may consist of fibreglass media with a minimum thickness of 12,7 mm and a
3 1)
minimum density of 9,5 kg/m . The fibre diameter shall be 0,76 µm to 1,27 µm and the moisture
absorption should be less than 1 % by mass after exposure to 50 °C and 95 % relative humidity for 96 h.
The absolute filter media shall be installed with nap side facing upstream, in an airtight holder that
adequately supports the media. The face velocity shall not exceed approximately 0,8 m/s to maintain
media integrity.
As an alternative, a non-woven filter media with the efficiency described in 5.3.2 may be used.
To reduce any subsequent errors in the measurements caused by losses of fibres or materials, the
absolute filter shall be subject to a flow of at least 110 % of the rated flow of ambient air for a minimum
of 5 min before the first (new) test weighing.
NOTE The use of an absolute filter with a backing will minimize fibre loss.
5.3.2 Validation of absolute filter media efficiency, E
a
Arrange two absolute filters in tandem. Perform a filter efficiency test and determine the mass increase
of each absolute filter according to the test procedure given in 6.4.3 or 7.5.2:
Δm
A
E = ×100 (1)
a
ΔΔmm+
AB
where
E is the absolute filter efficiency, expressed as a percentage;
a
Δm is the mass increase of the upstream absolute filter;
A
Δm is the mass increase of the downstream absolute filter.
B
The absolute filter efficiency should be a minimum of 99 % for the contaminant presented to it.
5.4 Absolute filter mass
The absolute filter shall be weighed, to the nearest 0,01 g, after the mass has stabilized. Weight
stabilization may be achieved by storage in a ventilated oven at a constant temperature of 105 °C ± 5 °C.
The absolute filter shall be weighed inside the oven. Alternatively, air conditioned following 5.5 may
be drawn through the absolute filter for 15 min and then the filter is weighed. Evaluate conditioning
method per 5.4.1.
1)  A suitable material is commercially available. Details may be obtained from the secretariat of ISO/TC 22.
© ISO 2020 – All rights reserved 5

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ISO 5011:2020(E)

5.4.1 Validation of the absolute filter weighing method
Using the method of choice, the absolute pad weight method shall be performed once each day for three
days and evaluate results per Annex H.
5.5 Temperature and humidity
All tests shall be conducted with air entering the air cleaner at a temperature of 23 °C ± 5 °C. Tests shall
be conducted at a relative humidity of (55 ± 15) %, the permissible variation at each weighing stage
throughout each single test being ±2 %.
The test results of an air cleaner will be affected by the relative humidity of the air passing through it
and the results of otherwise identical tests carried out near the two extremes of the permitted range of
relative humidity may not be directly comparable. The tests should be conducted w
...

FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 5011
ISO/TC 22/SC 34
Inlet air cleaning equipment for
Secretariat: ANSI
internal combustion engines and
Voting begins on:
2020­06­08 compressors — Performance testing
Voting terminates on:
Séparateurs aérauliques placés à l'entrée des moteurs à combustion
2020­08­03
interne et des compresseurs — Détermination des performances
RECIPIENTS OF THIS DRAFT ARE INVITED TO
SUBMIT, WITH THEIR COMMENTS, NOTIFICATION
OF ANY RELEVANT PATENT RIGHTS OF WHICH
THEY ARE AWARE AND TO PROVIDE SUPPOR TING
DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
ISO/FDIS 5011:2020(E)
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN­
DARDS TO WHICH REFERENCE MAY BE MADE IN
©
NATIONAL REGULATIONS. ISO 2020

---------------------- Page: 1 ----------------------
ISO/FDIS 5011:2020(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH­1214 Vernier, Geneva
Phone: [phone]
Fax: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved

---------------------- Page: 2 ----------------------
ISO/FDIS 5011:2020(E)

Contents Page
Foreword .v
1 Scope . 1
2 Normative references . 1
3 Terms, definitions and symbols . 1
3.1 Terms and definitions . 1
3.2 Symbols . 3
4 Measurement accuracy and standard conditions . 4
4.1 Measurement accuracy and precision . 4
4.2 Standard conditions . 4
5 Test materials and test conditions . 4
5.1 Test dust . 4
5.1.1 Grade . 4
5.1.2 Preparation . 4
5.2 Test oil for oil bath air cleaners . 5
5.3 Absolute filter materials . 5
5.3.1 Filter media . 5
5.3.2 Validation of absolute filter media efficiency, E . 5
a
5.4 Absolute filter mass . 5
5.5 Temperature and humidity . 6
6 Test procedure for dry-type air cleaners for automotive applications .6
6.1 General . 6
6.2 Test equipment . 6
6.3 Restriction and differential pressure test . 8
6.4 Efficiency test . 8
6.4.1 Purpose . 8
6.4.2 Types . 8
6.4.3 Test procedure — Absolute filter method . 9
6.4.4 Test procedure — Direct weighing method .10
6.5 Capacity test .10
6.6 Filter element pressure collapse test.11
6.7 Variable air flow test .11
6.8 Presentation of data .12
7 Test procedure for dry-type air cleaners for industrial applications .12
7.1 General .12
7.2 Test equipment .12
7.3 Restriction and differential pressure test .13
7.4 Initial efficiency test procedure — Absolute filter method .13
7.5 Full-life efficiency and capacity test.14
7.5.1 Air cleaner dust capacity .14
7.5.2 Test procedure — Absolute filter method .14
7.5.3 Test procedure — Direct weighing method .16
7.6 Presentation of data .16
7.7 Scavenged air cleaner performance test .16
7.7.1 General.16
7.7.2 Additional equipment . .17
7.7.3 Restriction and differential pressure test .17
7.7.4 Full-life efficiency and capacity test .17
7.7.5 Presentation of data .18
7.8 Precleaner performance test .18
7.8.1 Precleaner dust removal .18
7.8.2 Precleaner efficiency .19
7.8.3 Presentation of data .19
© ISO 2020 – All rights reserved iii

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ISO/FDIS 5011:2020(E)

7.9 Secondary element test procedure .19
7.9.1 General.19
7.9.2 Specific efficiency test .19
7.9.3 Expression of results .20
8 Test procedure for industrial applications of oil bath air cleaners.20
8.1 General .20
8.2 Test equipment and conditions .20
8.3 Restriction and differential pressure test .21
8.4 Oil carry-over test .21
8.5 Full life efficiency and capacity test .21
8.6 Recovery test .22
8.7 Presentation of data .22
Annex A (normative) Explanation of restriction, differential pressure and pressure loss of
an air cleaner .23
Annex B (normative) Test equipment .25
Annex C (informative) Report sheet on performance testing of air cleaner equipment
according to ISO 5011 — Automotive application .35
Annex D (informative) Report sheet on performance testing of air cleaner equipment
according to ISO 5011 — Industrial application .36
Annex E (informative) Presentation of results — Air cleaner restriction/differential
pressure versus flow.38
Annex F (informative) Presentation of results — Air cleaner capacity .39
Annex G (normative) Airflow and resistance corrections to standard conditions .40
Annex H (normative) Penetration sensitivity .42
Bibliography .50
iv © ISO 2020 – All rights reserved

---------------------- Page: 4 ----------------------
ISO/FDIS 5011:2020(E)

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 non­governmental, 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
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see 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.
This fourth edition cancels and replaces the third edition (ISO 5011:2014), which has been technically
revised. It also incorporates the Amendment ISO 5011:2014/Amd.1:2018. The main changes compared
to the previous edition are as follows:
— Added a validation procedure for verifying efficiency measurements.
— Revised recommended ISO dust injector table.
— Added formula for precleaner efficiency method.
— Removed requirement for secondary element collapse test.
— Added Annex H (Penetration sensitivity).
— Added a new dust injector.
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.
© ISO 2020 – All rights reserved v

---------------------- Page: 5 ----------------------
FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 5011:2020(E)
Inlet air cleaning equipment for internal combustion
engines and compressors — Performance testing
1 Scope
This document establishes and specifies uniform test procedures, conditions, equipment, and a
performance report to permit the direct laboratory performance comparison of air cleaners.
The basic performance characteristics of greatest interest are air flow restriction or differential
pressure, dust collection efficiency, dust capacity, and oil carry-over on oil bath air cleaners. This test
code therefore deals with the measurement of these parameters.
This document is applicable to air cleaners used on internal combustion engines and compressors
generally used in automotive and industrial applications.
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 5167­1, Measurement of fluid flow by means of pressure differential devices inserted in circular cross-
section conduits running full — Part 1: General principles and requirements
ISO 12103­1, Road vehicles — Test contaminants for filter evaluation — Part 1: Arizona test dust
3 Terms, definitions and symbols
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:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1 Terms and definitions
3.1.1
air filter
air cleaner
device which removes particles suspended in the intake air as it is drawn into the engine
3.1.2
filter element
replaceable part of the air filter (3.1.1), consisting of the filter material and carrying frame
3.1.3
secondary element
air cleaner (3.1.1) element fitted downstream of the primary element for the purpose of providing the
engine with protection against dust in the event of
a) certain types of primary element failure, or
b) dust being present during the removal of the primary element for servicing
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3.1.4
unit under test
either a single air cleaner (3.1.1) element or a complete air cleaner assembly
3.1.5
single-stage air cleaner
air cleaner (3.1.1) which does not incorporate a separate precleaner (3.1.7)
3.1.6
multistage air cleaner
air cleaner (3.1.1) consisting of two or more stages, the first usually being a precleaner (3.1.7), followed
by one or more filter elements (3.1.2)
Note 1 to entry: If two elements are used, the first is called the primary element and the second one is called the
secondary element (3.1.3).
3.1.7
precleaner
device usually using inertial or centrifugal means to remove a portion of the test dust prior to reaching
the filter element (3.1.2)
3.1.8
test air flow
measure of the quantity of air drawn through the air cleaner (3.1.1) outlet per unit time
Note 1 to entry: The flow rate is expressed in cubic metres per minute corrected to standard conditions.
3.1.9
rated air flow
flow rate specified by the user or manufacturer
Note 1 to entry: It may be used as the test air flow (3.1.8).
3.1.10
scavenged air flow
measure of the quantity of air used to remove the collected dust from a precleaner (3.1.7)
Note 1 to entry: It is expressed as a percentage of the test air flow (3.1.8).
3.1.11
static pressure
pressure in a duct, at the observed air flow rate, measured by connecting a pressure gauge to a hole or
holes drilled in the wall of the duct
Note 1 to entry: In the tests specified in this document, a static pressure is measured by a manometer (usually a
liquid manometer) as a negative pressure difference against the atmospheric pressure and in the formula this is
treated as a positive value.
3.1.12
restriction
static pressure (3.1.11) measured immediately downstream of the unit under test (3.1.4)
3.1.13
differential pressure
difference in static pressure (3.1.11) measured immediately upstream and downstream of the unit under
test (3.1.4)
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3.1.14
pressure loss
measure of the loss of energy caused by an air cleaner (3.1.1) at the observed air flow rate
Note 1 to entry: It is expressed as the differential pressure (3.1.13) corrected for any difference in the dynamic
head at the measuring points.
Note 2 to entry: For further information, see Annex A.
3.1.15
absolute filter
filter downstream of the unit under test (3.1.4) that retains the contaminant passed by the unit under test
3.1.16
efficiency
ability of the air cleaner (3.1.1) or the unit to remove contaminant mass under specified test conditions
3.1.17
capacity
quantity of contaminant removed by the unit under test (3.1.4) in producing specified terminal
conditions
3.1.18
oil carry-over
appearance of oil at the cleaner outlet
3.1.19
test terminal condition
condition, relating to an air cleaner (3.1.1), the occurrence of which signifies the end of the test
Note 1 to entry: A test terminal condition may be, for example, any one of the following: the restriction (3.1.12)
or the differential pressure (3.1.13) reaches a specified or agreed terminal value; the dust-removing efficiency
(3.1.16) or some other performance parameter falls to a specified or agreed value; oil carry-over (3.1.18) occurs;
a dust pot becomes filled.
3.1.20
automotive application
air cleaner (3.1.1) generally used for internal combustion engines in passenger cars
3.1.21
industrial application
air cleaner (3.1.1) generally used for internal combustion engines in heavy-duty trucks, construction
equipment and agricultural tractors
3.2 Symbols
The following applied units, according to ISO 80000­1, are used.
Name Symbol Unit
3
Density ρ kg/m
Differential pressure Δp Pa
d
Mass m g
Mass flow rate q kg/min
m
Pressure p Pa
Pressure loss Δp Pa
l
Restriction Δp Pa
r
Temperature T °C
Time t s
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ISO/FDIS 5011:2020(E)

Name Symbol Unit
Velocity v m/s
3
Volume flow rate q m /min
V
4 Measurement accuracy and standard conditions
4.1 Measurement accuracy and precision
Measure the air flow rate to within ±2 % of the actual value, except for the variable air flow test when
accuracy may be ±2 % of the maximum value of the cyclic flow rate through the cleaner.
Measure the differential pressure and restriction to within 25 Pa for pressure readings up to 10 kPa,
within 1 % of reading for higher pressures.
Measure the temperature to within 0,5 °C of the actual value.
Measure the mass to within 0,1 g with the exception of absolute filter mass to be measured at 0,01 g and
with the exception of the feeder mass to be measured at 1 %.
Measure the relative humidity (RH) with an accuracy of ±2 % RH.
Measure the barometric pressure to within 0,3 kPa.
The measurement equipment shall be calibrated at regular intervals to ensure the required accuracy.
Follow Annex H to determine the reporting precision of your efficiency measurement.
4.2 Standard conditions
All airflow measurements shall be corrected to a standard condition of 20 °C at 101,3 kPa.
See Annex G.
5 Test materials and test conditions
5.1 Test dust
5.1.1 Grade
The test dust to be used shall be ISO 12103-1, A.2 (ISO fine) or ISO 12103-1, A.4 (ISO coarse), subject
to agreement between the filter manufacturer and client. The chemical analysis and the particle size
distribution shall conform to ISO 12103­1.
In the absence of an agreement on the dust
— for single-stage filters, use ISO fine test dust, and
— for multistage filters, use ISO coarse test dust.
5.1.2 Preparation
Before using the test dust, a quantity sufficient to cover the test requirements shall be mixed to
ensure that no stratification / clumping has occurred. The test dust shall then be allowed to become
acclimatised to a constant mass under the prevailing test conditions.
NOTE To ensure a constant rate of dust feed with some dust feeders, it can be found necessary to heat the
dust prior to being acclimated to the environment.
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ISO/FDIS 5011:2020(E)

5.2 Test oil for oil bath air cleaners
The oil used for testing oil bath air cleaners shall be that specified by the filter manufacturer and agreed
by the user for use at the appropriate ambient temperature. If an oil is not specified, the test oil shall be
a heavy-duty oil and the viscosity at the temperature of the test shall be adjusted as follows:
2
— 85 mm /s for oil carry-over and restriction/differential pressure tests;
2
— 330 mm /s for efficiency and capacity tests, including an oil carry-over test after the capacity test.
5.3 Absolute filter materials
5.3.1 Filter media
The absolute filter may consist of fibreglass media with a minimum thickness of 12,7 mm and
3 1)
a minimum density of 9,5 kg/m . The fibre diameter shall be 0,76 g to 1,27 µm and the moisture
absorption should be less than 1 % by mass after exposure to 50 °C and 95 % relative humidity for 96 h.
The absolute filter media shall be installed with nap side facing upstream, in an airtight holder that
adequately supports the media. The face velocity shall not exceed approximately 0,8 m/s to maintain
media integrity.
As an alternative, a non-woven filter media with the efficiency described in 5.3.2 may be used.
To reduce any subsequent errors in the measurements caused by losses of fibres or materials, the
absolute filter shall be subject to a flow of at least 110 % of the rated flow of ambient air for a minimum
of 5 min before the first (new) test weighing.
NOTE The use of an absolute filter with a backing will minimize fibre loss.
5.3.2 Validation of absolute filter media efficiency, E
a
Arrange two absolute filters in tandem. Perform a filter efficiency test and determine the mass increase
of each absolute filter according to the test procedure given in 6.4.3 or 7.5.2:
Δm
A
E = ×100% (1)
a
ΔΔmm+
AB
where
E is the absolute filter efficiency;
a
Δm is the mass increase of the upstream absolute filter;
A
Δm is the mass increase of the downstream absolute filter.
B
The absolute filter efficiency should be a minimum of 99 % for the contaminant presented to it.
5.4 Absolute filter mass
The absolute filter shall be weighed, to the nearest 0,01 g, after the mass has stabilized. Weight
stabilization may be achieved by storage in a ventilated oven at a constant temperature of 105 °C ± 5 °C.
The absolute filter shall be weighed inside the oven. Alternatively, air conditioned following 5.5 may
be drawn through the absolute filter for 15 min and then the filter is weighed. Evaluate conditioning
method per 5.4.1.
1)  A suitable material is commercially available. Details may be obtained from the secretariat of ISO/TC 22.
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ISO/FDIS 5011:2020(E)

5.4.1 Validation of the absolute filter weighing method
Using the method of choice, the absolute pad weight method shall be performed once e
...