EN ISO 29463-5:2018

High-efficiency filters and filter media for removing particles in air - Part 5: Test method for filter elements (ISO 29463-5:2011)

ISO 29463-5:2011 specifies the reference test procedure for determining the efficiency of filters at their most penetrating particle size (MPPS). ISO 29463-5:2011 also gives guidelines for the testing and classification for filters with an MPPS of less than 0,1 μm and filters using media with (charged) synthetic fibres. ISO 29463-5:2011 is intended for use in conjunction with ISO 29463-1, ISO 29463-2, ISO 29463-3 and ISO 29463-4.

Schwebstofffilter und Filtermedien zur Abscheidung von Partikeln aus der Luft - Teil 5: Prüfverfahren für Filterelemente (ISO 29463-5:2011)

Dieser Teil der ISO 29463 spezifiziert das Referenz-Prüfverfahren für die Bestimmung des Abscheidegrads von Filtern für die Partikelgröße im Abscheidegradminimum (MPPS). Er enthält außerdem Richtlinien für die Prüfung und Klassifizierung von Filtern mit einer Partikelgröße im Abscheidegradminimum (MPPS) von weniger als 0,1 μm (Anhang B) und Filtern, die Medien mit (geladenen) synthetischen Fasern (Anhang C) nutzen. Er sollte in Verbindung mit ISO 29463 1, ISO 29463 2, ISO 29463 3 und ISO 29463 4 verwendet werden.

Filtres à haut rendement et filtres pour l'élimination des particules dans l'air - Partie 5: Méthode d'essai des éléments filtrants (ISO 29463-5:2011)

La présente partie de l'ISO 29463 spécifie le mode opératoire d'essai de référence pour la détermination de l'efficacité des filtres pour la taille de particule ayant la plus forte pénétration (MPPS). Elle donne également des lignes directrices pour les essais et la classification des filtres avec une MPPS de moins de 0,1 µm (Annexe B) et des filtres utilisant des médias avec des fibres synthétiques (chargées) (Annexe C). Elle est destinée à être utilisée conjointement avec l'ISO 29463‑1, l'ISO 29463‑2, l'ISO 29463‑3 et l'ISO 29463‑4.

Zelo učinkoviti filtri in filtrirno sredstvo za odstranjevanje delcev iz zraka - 5. del: Metoda preskušanja filtrskih elementov (ISO 29463-5:2011)

ISO 29463-5:2011 določa referenčni preskusni postopek za ugotavljanje učinkovitosti filtrov pri velikosti delcev, ki omogoča največjo prepustnost (MPPS). ISO 29463-5:2011 podaja tudi smernice za preskušanje in klasifikacijo filtrov z vrednostjo MPPS manj kot 0,1 μm ter filtrov s sredstvom iz (naelektrenih) sintetičnih vlaken. ISO 29463-5:2011 je predviden za uporabo v povezavi s standardi ISO 29463-1, ISO 29463-2, ISO 29463-3 in ISO 29463-4.

General Information

• Status: Withdrawn
• Publication Date: 09-Oct-2018
• Withdrawal Date: 13-Apr-2025
• ICS: 91.140.30 - Ventilation and air-conditioning systems
• Technical Committee: CEN/TC 195 - Air filters for general air cleaning
• Drafting Committee: CEN/TC 195/WG 2 - HEPA and ULPA filters
• Current Stage: 9960 - Withdrawal effective - Withdrawal
• Start Date: 27-Apr-2022
• Completion Date: 14-Apr-2025
• Ref Project: SIST EN ISO 29463-5:2018 - High-efficiency filters and filter media for removing particles in air - Part 5: Test method for filter elements (ISO 29463-5:2011)

Relations

• Replaces: EN 1822-5:2009 - High efficiency air filters (EPA, HEPA and ULPA) - Part 5: Determining the efficiency of filter elements
• Effective Date: 12-Oct-2016
• Replaced By: EN ISO 29463-5:2022 - High-efficiency filters and filter media for removing particles in air - Part 5: Test method for filter elements (ISO 29463-5:2022)
• Effective Date: 15-May-2019

Standards Content (Sample)

SLOVENSKI STANDARD
01-december-2018
1DGRPHãþD
SIST EN 1822-5:2010
=HORXþLQNRYLWLILOWULLQILOWULUQRVUHGVWYR]DRGVWUDQMHYDQMHGHOFHYL]]UDNDGHO
0HWRGDSUHVNXãDQMDILOWUVNLKHOHPHQWRY,62
High-efficiency filters and filter media for removing particles in air - Part 5: Test method
for filter elements (ISO 29463-5:2011)
Schwebstofffilter und Filtermedien zur Abscheidung von Partikeln aus der Luft - Teil 5:
Prüfverfahren für Filterelemente (ISO 29463-5:2011)
Filtres à haut rendement et filtres pour l'élimination des particules dans l'air - Partie 5:
Méthode d'essai des éléments filtrants (ISO 29463-5:2011)
Ta slovenski standard je istoveten z: EN ISO 29463-5:2018
ICS:
13.040.99 Drugi standardi v zvezi s Other standards related to air
kakovostjo zraka quality
91.140.30 3UH]UDþHYDOQLLQNOLPDWVNL Ventilation and air-
VLVWHPL conditioning systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 29463-5
EUROPEAN STANDARD
NORME EUROPÉENNE
October 2018
EUROPÄISCHE NORM
ICS 91.140.30 Supersedes EN 1822-5:2009
English Version
High-efficiency filters and filter media for removing
particles in air - Part 5: Test method for filter elements
(ISO 29463-5:2011)
Filtres à haut rendement et filtres pour l'élimination Schwebstofffilter und Filtermedien zur Abscheidung
des particules dans l'air - Partie 5: Méthode d'essai des von Partikeln aus der Luft - Teil 5: Prüfverfahren für
éléments filtrants (ISO 29463-5:2011) Filterelemente (ISO 29463-5:2011)
This European Standard was approved by CEN on 6 May 2018.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2018 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 29463-5:2018 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
The text of ISO 29463-5:2011 has been prepared by Technical Committee ISO/TC 142 "Cleaning
equipment for air and other gases” of the International Organization for Standardization (ISO) and has
been taken over as EN ISO 29463-5:2018 by Technical Committee CEN/TC 195 “Air filters for general
air cleaning” the secretariat of which is held by UNI.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by April 2019, and conflicting national standards shall be
withdrawn at the latest by April 2019.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 1822-5:2009.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Endorsement notice
The text of ISO 29463-5:2011 has been approved by CEN as EN ISO 29463-5:2018 without any
modification.
INTERNATIONAL ISO
STANDARD 29463-5
First edition
2011-10-15
High-efficiency filters and filter media for
removing particles in air —
Part 5:
Test method for filter elements
Filtres à haut rendement et filtres pour l'élimination des particules dans
l'air —
Partie 5: Méthode d'essai des éléments filtrants

Reference number
ISO 29463-5:2011(E)
©
ISO 2011
ISO 29463-5:2011(E)
©  ISO 2011
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56  CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail [e-mail]
Web www.iso.org
Published in Switzerland
ii © ISO 2011 – All rights reserved

ISO 29463-5:2011(E)
Contents Page
Foreword . iv
Introduction . v
1  Scope . 1
2  Normative references . 1
3  Terms and definitions . 2
4  Description of the method . 2
4.1  Alternate efficiency test method for groups H and U filters . 3
4.2  Statistical efficiency test method for low efficiency filters — Group E filters . 3
5  Test filter . 3
6  Test apparatus . 4
6.1  Test duct . 4
6.2  Aerosol generation and measuring instruments . 6
7  Conditions of the test air . 10
8  Test procedure . 11
8.1  Preparatory checks . 11
8.2  Starting up the aerosol generator . 11
8.3  Preparation of the test filter . 11
8.4  Testing . 11
9  Evaluation . 12
10  Test report . 13
11  Maintenance and inspection of the test apparatus . 15
Annex A (normative) Alternate efficiency test method from scan testing . 16
Annex B (informative) Testing and classification method for filters with MPPS 0,1 µm
(e.g. membrane medium filters) . 17
Annex C (normative) Testing and classification of filters using media with (charged) synthetic
fibres . 20
Annex D (informative) Traditional efficiency test methods for HEPA and ULPA filters . 22
Bibliography . 23

ISO 29463-5:2011(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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
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.
ISO 29463-5 was prepared by Technical Committee ISO/TC 142, Cleaning equipment for air and other gases.
ISO 29463 consists of the following parts, under the general title High-efficiency filters and filter media for
removing particles in air:
 Part 1: Classification, performance, testing and marking
 Part 2: Aerosol production, measuring equipment, particle-counting statistics
 Part 3: Testing flat sheet filter media
 Part 4: Test method for determining leakage of filter element — Scan method
 Part 5: Test method for filter elements
iv © ISO 2011 – All rights reserved

ISO 29463-5:2011(E)
Introduction
ISO 29463 (all parts) is derived from EN 1822 (all parts) with extensive changes to meet the requests from
non-EU p-members. It contains requirements, fundamental principles of testing and the marking for high-
efficiency particulate air filters with efficiencies from 95 % to 99,999 995 % that can be used for classifying
filters in general or for specific use by agreement between users and suppliers.
ISO 29463 (all parts) establishes a procedure for the determination of the efficiency of all filters on the basis of
a particle counting method using a liquid (or alternatively a solid) test aerosol, and allows a standardized
classification of these filters in terms of their efficiency, both local and overall efficiency, which actually covers
most requirements of different applications. The difference between ISO 29463 (all parts) and other national
standards lies in the technique used for the determination of the overall efficiency. Instead of mass
relationships or total concentrations, this technique is based on particle counting at the most penetrating
particle size (MPPS), which is, for micro-glass filter mediums, usually in the range of 0,12 μm to 0,25 μm. This
method also allows testing ultra-low-penetration air filters, which was not possible with the previous test
methods because of their inadequate sensitivity. For membrane filter media, separate rules apply, and are
described in Annex B. Although no equivalent test procedures for testing filters with charged media is
prescribed, a method for dealing with these types of filters is described in Annex C. Specific requirements for
testing method, frequency, and reporting requirements can be modified by agreement between supplier and
customer. For lower-efficiency filters (group H, as described below), alternate leak test methods described in
ISO 29463-4:2011, Annex A, can be used by specific agreement between users and suppliers, but only if the
use of these other methods is clearly designated in the filter markings as noted in ISO 29463-4:2011, Annex A.
There are differences between ISO 29463 (all parts) and other normative practices common in several
countries. For example, many of these rely on total aerosol concentrations rather than individual particles. For
information, a brief summary of these methods and their reference standards are provided in Annex D of this
part of ISO 29463.
INTERNATIONAL STANDARD ISO 29463-5:2011(E)

High-efficiency filters and filter media for removing particles in
air —
Part 5:
Test method for filter elements
1 Scope
This part of ISO 29463 specifies the reference test procedure for determining the efficiency of filters at their
most penetrating particle size (MPPS). It also gives guidelines for the testing and classification for filters with
an MPPS of less than 0,1 μm (Annex B) and filters using media with (charged) synthetic fibres (Annex C). It is
intended for use in conjunction with ISO 29463-1, ISO 29463-2, ISO 29463-3 and ISO 29463-4.
2 Normative references
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
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/TS 21220:2009, Particulate air filters for general ventilation — Determination of filtration performance
ISO 21501-4, Determination of particle size distribution — Single particle light interaction methods — Part 4:
Light scattering airborne particle counter for clean spaces
ISO 29463-1:2011, High-efficiency filters and filter media for removing particles in air — Part 1: Classification,
performance, testing and marking
ISO 29463-2:2011, High-efficiency filters and filter media for removing particles in air — Part 2: Aerosol
production, measuring equipment, particle-counting statistics
ISO 29463-3, High-efficiency filters and filter media for removing particles in air — Part 3: Testing flat sheet
filter media
ISO 29463-4:2011, High-efficiency filters and filter media for removing particles in air — Part 4: Test method
for determining the leakage of filter elements — Scan method
1)
ISO 29464 , Cleaning equipment for air and other gases — Terminology

1) To be published.
ISO 29463-5:2011(E)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 29463-1, ISO 29463-2, ISO 29463-3,
ISO 29463-4, ISO 29464 and the following apply.
3.1
sampling duration
time during which the particles in the sampling volume flow are counted (upstream or downstream)
3.2
measuring procedure with fixed sampling probes
determination of the overall efficiency using fixed sampling probes upstream and downstream of the test filter
3.3
total particle count method
particle counting method in which the total number of particles in a certain sample volume is determined
without classification according to size
EXAMPLE By using a condensation particle counter.
3.4
particle counting and sizing method
particle counting method which allows both the determination of the number of particles and also the
classification of the particles according to size
EXAMPLE By using an optical particle counter.
3.5
particle concentration method
method that can determine the total concentration of particles in the aerosol either by multiple particle
counting or chemical concentrations
NOTE No particle size classification can be determined by this method.
4 Description of the method
In order to determine the efficiency of the test filter, it is fixed in the test filter mounting assembly and
subjected to a test air volume flow corresponding to the nominal volume flow rate. After measuring the
pressure drop at the nominal volume flow rate, the filter is purged with clean air and the test aerosol produced
by the aerosol generator is mixed with the prepared test air along a mixing section, so that it is spread
homogeneously over the cross-section of the duct.
The efficiency is always determined for the MPPS; see ISO 29463-3. The size distribution of the aerosol
particles can optionally be measured using a particle size analysis system, for example, a differential mobility
particle sizer, DMPS.
The testing can be carried out using either a mono-disperse or poly-disperse test aerosol. When testing with
(quasi-) mono-disperse aerosol, the total particle counting method may be used with a condensation particle
counter (CPC) or an optical particle counter (OPC; for example a laser particle counter). It shall be ensured
that the number median particle diameter corresponds to the MPPS, i.e. the particle diameter at which the
filter medium has its minimum efficiency.
2 © ISO 2011 – All rights reserved

ISO 29463-5:2011(E)
When using a poly-disperse aerosol, the particle counting method, e.g. an optical particle counter or DMPS,
shall be used, which, in addition to counting the particles, is also able to determine their size distribution. It shall
be ensured that the count median diameter, D , of the test aerosol lies in the range given by Equation (1):
M
S
MPPS
DS1,5 (1)
M MPPS
where S is the most penetrating particle size.
MPPS
In order to determine the overall efficiency, representative partial flows are extracted on the upstream and
downstream sides of the filter element and directed to the attached particle counter via a fixed sampling probe
to measure the number of particles. It is necessary to have a mixing section behind the test filter to mix the
aerosol homogeneously with the test air over the duct cross-section (see 6.1.4).
4.1 Alternate efficiency test method for groups H and U filters
The standard efficiency test method, as described above, uses downstream mixing and a fixed downstream
probe. However, an alternate efficiency test method using scan test equipment with moving probe(s) is
provided and described in Annex A.
4.2 Statistical efficiency test method for low efficiency filters — Group E filters
For filters of group E, the overall efficiency shall be determined by one of the statistical test procedures
described below and it is not necessary to carry out the test for each single filter element (as is mandatory for
filters of groups H and U). The overall efficiency of group E filters shall be determined by averaging the results
of the statistical leak test as described below.
A record of the filter data in the form of a type test certificate or alternatively a factory test certificate is
required. However, the supplier shall be able to provide documentary evidence to verify the published filter
data upon request. This can be done by either:
a) maintaining a certified quality management system (e.g. ISO 9000), which requires the application of
statistically based methods for testing and documenting efficiency for group E filters in accordance with
this part of ISO 29463; or
b) using accepted statistical methods to test all of production lots of filters.
The skip lot procedure as described in ISO 2859-1 or any equivalent alternative method may be used.
The skip lot procedure as described in ISO 2859-1 implies that at the beginning, the test frequency is high
and is, in the course of further testing, reduced as the production experience grows and the products
produced conform to the target. For example, for the first eight production lots, 100 % of the produced
filters are tested. If all the tests are positive, the frequency is reduced to half for the next eight production
lots. If all the tests are positive again, the number is reduced by half again, and so on until it is necessary
to test only one out of eight lots (e.g. the minimum test frequency). Each time one of the tested filters fails,
the test frequency is doubled again. In any case, the number of samples per lot tested shall be greater
than three filters.
5 Test filter
The filter element being tested shall show no signs of damage or any other irregularities. The filter element
shall be handled carefully and shall be clearly and permanently marked with the following details:
 designation of the filter element;
 upstream side of the filter element.
The temperature of the test filter during the testing shall correspond with that of the test air.
ISO 29463-5:2011(E)
6 Test apparatus
A flow sheet showing the arrangement of apparatus comprising a test rig is given in ISO 29463-1:2011,
Figure 4. An outline diagram of a test rig is given in Figure 1.
The fundamentals of aerosol generation and neutralization with details of suitable types of equipment as well
as detailed descriptions of the measuring instruments required for the testing are given in ISO 29463-2.

Key
1 coarse dust filter
2 fine dust filter
3 fan
4 air heating
5 high-efficiency air filter
6 aerosol inlet to the test duct
7 temperature measurement
8 hygrometer
9 sampler, particle size analysis
10 sampler, upstream
11 ring pipe for differential pressure measurement
12 manometer
13 test filter mounting assembly
14 measuring damper (see ISO 5167-1)
15 measurement of absolute pressure
16 manometer measuring differential pressure
17 sampler, downstream
Figure 1 — Example of a test rig
6.1 Test duct
6.1.1 Test air conditioning
The test air conditioning equipment shall be comprised of the equipment required to control the condition of
the test air so that it can be brought in compliance with the requirement of Clause 7.
4 © ISO 2011 – All rights reserved

ISO 29463-5:2011(E)
6.1.2 Adjustment of the volume flow rate
Filters shall always be tested at their nominal air flow rate. It shall be possible to adjust the volume flow rate by
means of a suitable provision (e.g. by changing the speed of the fan, or with dampers) to a value 5 % of the
nominal flow rate, which shall then remain constant within 2 % throughout each test.
6.1.3 Measurement of the volume flow rate
The volume flow rate shall be measured using a standardized or calibrated method (e.g. measurement of the
differential pressure using standardized damper equipment, such as orifice plates, nozzles, Venturi tubes in
accordance with ISO 5167-1.
The limit error of measurement shall not exceed 5 % of the measured value.
6.1.4 Aerosol mixing section
The aerosol input and the mixing section (see Figure 1 for an example) shall be so constructed that the
aerosol concentration measured at individual points of the duct cross-section, directly in front of the test filter,
do not deviate by more than 10 % from the mean value of at least nine measuring points over the channel
cross-section.
6.1.5 Test filter mounting assembly
The test filter mounting assembly shall ensure that the test filter can be sealed and subjected to flow in
accordance with requirements.
It shall not obstruct any part of the filter cross-sectional area.
6.1.6 Measuring points for the pressure drop
The measuring points for pressure drop shall be so arranged that the mean value of the static pressure in the
flow upstream and downstream of the filter can be measured. The planes of the pressure measurements
upstream and downstream shall be positioned in regions of an even flow with a uniform flow profile.
In rectangular or square test ducts, smooth holes with a diameter of 1 mm to 2 mm for the pressure
measurements shall be bored in the middle of the channel walls, normal to the direction of flow. The four holes
shall be interconnected with a circular pipe.
6.1.7 Sampling
In order to determine the efficiency, partial flows are extracted from the test volume flow by sampling probes
and led to the particle counters. The diameter of the probes shall be chosen so that isokinetic conditions are
maintained in the duct at the given volume flow rate for the sample. In this way, sampling errors can be
neglected due to the small size of the particles in the test aerosol. The connections to the particle counter
shall be as short as possible. Samples on the upstream side are taken by a fixed sampling probe in front of
the test filter. The sampling shall be representative, on the basis that the aerosol concentration measured from
the sample does not deviate by more than 10 % from the mean value determined in accordance with 6.1.4.
A fixed sampling probe is also installed downstream, preceded by a mixing section that ensures a
representative measurement of the downstream aerosol concentration. This is taken to be the case when, in
event of an artificially made big leak in the test filter, the aerosol concentration measured downstream the filter
does not at any point deviate by more than 10% from the mean value of at least nine measuring points over
the duct cross-section. It is necessary, however, to verify beforehand that the artificially made leak is big
enough to increase the filter penetration by at least a factor of five relative to the penetration of the non-
leaking filter.
The mean aerosol concentrations determined at the upstream and downstream sampling points without the
filter in position shall not differ from each other by more than 5 %.
ISO 29463-5:2011(E)
6.2 Aerosol generation and measuring instruments
The operating parameters of the aerosol generator shall be adjusted to produce a test aerosol whose number
median diameter is in the range of the MPPS for the sheet filter medium.
The median size of the mono-disperse test aerosol shall not deviate from the MPPS by more than 10 %. A
deviation of 50 % is allowed when using a poly-disperse aerosol.
The particle output of the aerosol generator shall be adjusted according to the test volume flow rate and the
filter efficiency, so that the counting rates on the upstream and downstream sides lie under the coincidence
limits of the counter (maximum coincidence error of 10 % in accordance with ISO 21501-4), and significantly
above the zero count rate of the instruments.
The number distribution concentration of the test aerosol can be determined using a suitable particle size
analysis system (e.g. a differential mobility particle sizer, DMPS) or with a laser particle counter suitable for
these test purposes. The limit error of the measurement method used to determine the number median value
shall not exceed 20 % relative to the measurement value.
The number of counted particles measured upstream and downstream shall be sufficiently large to provide
statistically meaningful results, without the concentration exceeding the measuring range of the upstream
particle counter. If the upstream number concentration exceeds the range of the particle counter (in the
counting mode), a dilution system shall be inserted between the sampling point and the counter.
The particle counting may be carried out using either a pair of counters operating in parallel on the upstream
and downstream sides, or using a single counter to measure the number concentrations on the upstream and
downstream sides alternately. If measurements are made with only one counter, it shall be ensured that the
relevant properties of the test aerosol (for example, the number concentration, particle size distribution,
homogeneous distribution over the channel cross-section) remain constant over time. If two counters are used
in parallel, both should be of the same type and calibrated as dual devices.
6.2.1 Apparatus for testing with a mono-disperse test aerosol
For technical reasons, the particle size distribution produced by the aerosol generator is usually quasi-mono-
disperse.
When using a mono-disperse aerosol for the efficiency testing of the filter element, not only optical particle
counters but also condensation particle counters may be used.
When using a condensation particle counter, it shall be ensured that the test aerosol does not contain
appreciable numbers of particles that are very much smaller than the MPPS. Such particles, which can be
produced, for example, by an aerosol generator that is no longer working properly, are also counted by a
condensation particle counter and can lead to a considerable error in the determination of the efficiency. One
way of checking for this error is to determine the number distribution of the test aerosol with a measuring
device that stretches over a range from the lower range limit of the condensation particle counter up to a
particle size of approximately 1 μm. The number distribution thus determined shall be quasi-mono-disperse
and without the large concentration of very small particles.
The apparatus for testing with mono-disperse aerosol is shown in Figure 2.
6.2.2 Apparatus for testing with a poly-disperse test aerosol
When determining the efficiency of a filter element using a poly-disperse test aerosol, the particle number
concentration and size distribution shall be determined using an optical particle counter (e.g. laser particle
counters).
The test apparatus for testing with a poly-disperse aerosol is shown in Figure 3.
6 © ISO 2011 – All rights reserved

ISO 29463-5:2011(E)
Key
1 pre-filter for test air
2 fan with variable speed control
3 air heater
4 aerosol inlet in the duct
5 aerosol generator for the mono-disperse aerosol
6 measurement of temperature, barometric pressure and relative humidity
7 upstream side mixing section
8 sampling point for particle size analysis
9 particle size analysis system (DMPS or OPC)
10 sampling point for upstream particle counting
11 dilution system (optional)
12 upstream particle counter (CPC or OPC)
13 test filter
14 measurement of pressure drop across the test filter
15 measurement of absolute pressure and volume air flow rate
16 downstream mixing section
17 sampling point for downstream particle counting
18 downstream particle counter (CPC or OPC)
19 computer for purposes of control and measurement recording
Figure 2 — Apparatus for testing with a mono-disperse aerosol
ISO 29463-5:2011(E)
Key
1 pre-filter for test air
2 fan with variable speed control
3 air heater
4 aerosol inlet in the duct
5 aerosol generator for the poly-disperse aerosol
6 measurement of temperature, barometric pressure and relative humidity
7 upstream side mixing section
8 sampling point for upstream particle count
9 dilution system (optional)
10 upstream OPC
11 test filter
12 measurement of pressure drop of the test filter
13 measurement of absolute pressure and volume air flow rate
14 downstream mixing section
15 sampling point for downstream particle count
16 downstream OPC
17 computer for control and measurement recording
Figure 3 — Apparatus for testing with a poly-disperse aerosol
8 © ISO 2011 – All rights reserved

ISO 29463-5:2011(E)
At a minimum, the measuring range of the optical particle counter used for efficiency testing shall cover at
S
MPPS
least the particle size range between and 1,5 S , where S is the most penetrating particle
MPPS MPPS
1,5
size.
The distribution of the channel limits shall be such that there is one (lower) channel limit in the diameter range
SS
MPPS MPPS
between and (Figure 4, range II a) and one (upper) channel limit in the diameter range
21,5
between 1,5  S and 2  S (Figure 4, range II b). From a practical point of view, for most common
MPPS MPPS
filter media in use, diameter channels of 0,1 μm to 0,2 μm and 0,2 μm to 0,3 μm, readily available in most
commercial optical particle counters, should sufficiently meet this requirement.
Specifically, for the different ranges of MPPS that are commonly encountered, the recommended measuring
range of the optical particle counter used in testing efficiency shall cover the following particle sizes given in
Equation (1) (Figure 4, range I):
S
MPPS
to 1,5 S (1)
MPPS
1,5
where S is the most penetrating particle size.
MPPS
The distribution of the size classes shall be such that each of the class limits meets one of the conditions
given in either Equation (2) (as shown in Figure 4, range II a) or Equation (3) (as shown in Figure 4,
range II b):
SS
MPPS MPPS
C (2)
LL
21,5
where C is the lower channel limit.
LL
1,5SC 2S (3)
MPPS UL MPPS
where C is the upper channel limit.
UL
All channels between these two limits can be evaluated to determine the filter efficiency. However, it is not
required for there to be more than one channel, so that the above condition can also be met, in an extreme
case, by only one channel.
ISO 29463-5:2011(E)
Figure 4 — Particle size efficiency, E, and permissible measuring ranges
relative to efficiency minimum (MPPS equal to0,18 μm) and number distribution, f,
of a poly-disperse test aerosol with d equal to 0,23 μm
p
7 Conditions of the test air
The test air shall be conditioned before being mixed with the test aerosol such that its temperature, relative
humidity and purity comply with the requirements specified in ISO 29463-1:2011, 7.3.
10 © ISO 2011 – All rights reserved

ISO 29463-5:2011(E)
8 Test procedure
8.1 Preparatory checks
After switching on the test apparatus the following parameters shall be checked.
a) Operational readiness of the measuring instruments:
The condensation particle counters shall be filled with operating liquid.
The warming-up times specified by the instrument makers shall be observed.
b) Zero count rate of the particle counter:
The measurement of the zero count rate shall be carried out using flushing air that is free from particles.
c) Absolute pressure, temperature and relative humidity of the test air.
These parameters shall be checked to ensure that they are in accordance with ISO 29463-1:2011, 7.3, and if
they are not, appropriate corrections shall be made.
8.2 Starting up the aerosol generator
When starting up the aerosol generator, a stand-by filter element shall be installed in the test filter mounting
assembly.
After adjusting the operating parameters of the aerosol generator and observing an appropriate warming-up
period, the particle concentration and the distribution of the test aerosol shall be checked to ensure that they
are in accordance with 6.2. The test aerosol distribution and concentration shall be determined as close to the
filter mounting assembly as possible.
8.3 Preparation of the test filter
8.3.1 Installation of the test filter
The test filter shall be handled in such a way as to ensure that the filter material is not damaged.
The test filter shall be installed in the mounting assembly with proper regard to air flow direction and gasketing
side.
The seal between the test filter and the test filter mounting assembly shall be free from leaks.
8.3.2 Flushing the test filter
In order to reduce the self-emission of particles by the test filter and to equalize the temperatures of the test
filter and the test air, the test filter shall be flushed with test air for a suitably long period at the nominal volume
flow rate. Following this, the residual self-emission may be measured at the downstream particle counter.
8.4 Testing
8.4.1 Measuring the pressure drop
The pressure drop across the test filter shall be measured in the unloaded state using the pure test air. The
nominal volume flow rate shall be set up in accordance with 6.1.2. The measurements shall be made when a
stable operating state has been reached.
ISO 29463-5:2011(E)
8.4.2 Testing with a mono-disperse test aerosol
In the mixing section, the test air is mixed with test aerosol, the median diameter of which corresponds to the
particle size, MPPS, at the efficiency minimum of the sheet filter medium (deviation 10 %; see 6.2).
The particle concentrations are measured on the upstream and downstream sides. This may be carried out
using either a pair of counters operating in parallel or a single counter to measure the particle concentrations
on the upstream and downstream sides alternately. The upstream particle number concentration and the
duration of measurement shall be chosen so that the difference between the counted and minimum particle
number on the upstream side (corresponding to the lower limit of the 95 % confidence range of a Poisson
distribution; see ISO 29463-2) does not vary by more than 5 % from the measured particle number (which
corresponds to at least 1,5  10 particles). On the downstream side, the difference between the maximum
particle number (corresponding to the upper limit of the 95 % confidence range of a Poisson distribution; see
ISO 29463-2) and the counted particle number shall not deviate by more than 20 % (which corresponds to at
least 100 particles) from the measured particle number (see Table 1).
When choosing the measurement duration, care shall be taken that the test filter is not overburdened with
aerosol.
8.4.3 Testing with a poly-disperse test aerosol
The testing is done in accordance with 8.4.2 using a poly-disperse aerosol, the median diameter of which shall
not deviate from the MPPS by more than 50 % (see 6.2).
When testing with a poly-disperse test aerosol, in contrast to the testing with a mono-disperse test aerosol, the
number distribution concentration and the number concentration are measured using optical particle counters.
In order to determine the efficiency, the upstream and downstream number concentrations are collected for all
S
MPPS
size classes which lie entirely or partially in the range to 1,5 S (see 6.2.2).
MPPS
1,5
9 Evaluation
The penetration, P, expressed as a percentage, is calculated as given in Equation (4):
c
N,d
P (4)
c
N,u
where
N
d
c is the number concentration downstream, equal to ;
N,d

Vt
s,d d
kN
Du
c is the number concentration upstream, equal to ;
N,u

Vt
s,u u
where
N is the number of particles counted upstream;
u
N is the number of particles counted downstream;
d
k is the dilution factor;
D

V is the sampling volume flow rate upstream;
s,u
12 © ISO 2011 – All rights reserved

ISO 29463-5:2011(E)

V is the sampling volume flow rate downstream;
s,d
t is the sampling duration upstream;
u
t is the sampling duration downstream.
d
The efficiency, E, expressed as a percentage, is calculated as given in Equation (5):
EP1 (5)
In order to calculate the minimum efficiency, E , the less favourable limit value for the 95 % confidence
95 %min
range for the actual particle count shall be used as the basis for the calculations. The calculation shall be
carried out taking into account the particle counting statistics specified in ISO 29463-2:2011, Clause 7. The
values for the 95 % confidence range shall be calculated only with pure counting data, without corrections
being made for the dilution factor. The minimum efficiency, E , expressed as a percentage, taking into
95 %min
account the particle counting statistics, is given by Equation (6):

c
N,d,95 %max
E 1 100 (6)
95 %min

c
N,u,95 %min

where
N
d,95 %max
c is the maximum downstream particle number concentration, equal to ;
N,d,95 %max
Vt
s,d d
Nk
u,95 %min D
c is the minimum upstream particle number concentration, equal to ;
N,u,95 %min
Vt
s,u u
N is the upper limit of the 95 % confidence range of the particle count downstream, calculated
d,95 %max
in accordance with ISO 29463-2, equal to NN1,96 ;
d
d
N is the lower limit of the 95 % confidence range of the particle count upstream, calculated in
u,95 %min
accordance with ISO 29463-2, equal to NN 1,96 .
uu
If the manufacturers' instructions for the particle counter include coincidence corrections for the measured
concentrations, then these shall be taken into account in the evaluation.
For the minimum efficiency, allowance is made only for measurement uncertainty due to low count rates.
The minimum efficiency is the basis of the classification in accordance with ISO 29463-1.
Table 1 shows a specimen calculation of the statistical uncertainty for the measurement of the efficiency.
10 Test report
The test report on the efficiency testing of a filter element shall contain at least the following information:
a) general information about the testing:
1) filter element (type and dimensions),
2) type of particle counters used,
ISO 29463-5:2011(E)
3) nominal volume flow rate,
4) particle size at the minimum efficiency of the filter medium MPPS,
5) test aerosol (substance, median diameter, geometrical standard deviation, concentration),
6) dilution factor (upstream);
b) test results:
1) pressure drop across the
...