ISO/TS 11155-2:2002

Road vehicles — Air filters for passenger compartments — Part 2: Test for gaseous filtration

ISO/TS 11155-2:2002 specifies a test comprising methods for measuring the dynamic gas adsorption of air filters in the passenger compartments of road vehicles. These laboratory test methods are applicable to air filters that improve air quality by reducing concentrations of gaseous, odorous or hazardous components from ambient or recirculated air, or both, in the vehicle cabin. They provide a means of measuring air pressure loss, as well as gas and vapour removal characteristics.

Véhicules routiers — Filtres à air pour l'habitacle — Partie 2: Essai pour le filtrage des gaz

General Information

• Status: Withdrawn
• Publication Date: 07-Nov-2002
• Withdrawal Date: 07-Nov-2002
• ICS: 43.040.60 - Bodies and body components
• Technical Committee: ISO/TC 22 - Road vehicles
• Drafting Committee: ISO/TC 22 - Road vehicles
• Current Stage: 9599 - Withdrawal of International Standard
• Completion Date: 05-Jan-2009

Relations

• Revised: ISO 11155-2:2009 - Road vehicles — Air filters for passenger compartments — Part 2: Test for gaseous filtration
• Effective Date: 15-Apr-2008

Standards Content (Sample)

TECHNICAL ISO/TS
SPECIFICATION 11155-2
First edition
2002-11-01

Road vehicles — Air filters for passenger
compartments —
Part 2:
Test for gaseous filtration
Véhicules routiers — Filtres à air pour l'habitacle —
Partie 2: Essai pour le filtrage des gaz




Reference number
ISO/TS 11155-2:2002(E)
©
ISO 2002

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ISO/TS 11155-2:2002(E)
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ii © ISO 2002 – All rights reserved

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ISO/TS 11155-2:2002(E)
Contents Page
Foreword . iv
1 Scope. 1
2 Normative references. 1
3 Terms and definitions. 1
4 Measurement accuracy. 4
5 General conditions. 4
6 Test contaminants. 5
7 Test equipment. 6
8 Experimental determination of t , using t . 7
0 lag
9 Preparation of filter/filter-element for testing. 8
10 Test methods. 8
11 System validation. 9
12 Documentation. 10
Annex A (normative) Recommended test stand configuration . 12
Annex B (informative) Detailed definition and calculation of t and t . 13
0 lag
Annex C (informative) Capacity determination. 15
Annex D (informative) Conversion of units, and possible test gases and concentrations . 16
Bibliography. 17



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ISO/TS 11155-2:2002(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 3.
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.
In other circumstances, particularly when there is an urgent market requirement for such documents, a technical
committee may decide to publish other types of normative document:
 an ISO Publicly Available Specification (ISO/PAS) represents an agreement between technical experts in an
ISO working group and is accepted for publication if it is approved by more than 50 % of the members of the
parent committee casting a vote;
 an ISO Technical Specification (ISO/TS) represents an agreement between the members of a technical
committee and is accepted for publication if it is approved by 2/3 of the members of the committee casting a
vote.
An ISO/PAS or ISO/TS is reviewed after three years with a view to deciding whether it should be confirmed for a
further three years, revised to become an International Standard, or withdrawn. In the case of a confirmed ISO/PAS
or ISO/TS, it is reviewed again after six years at which time it has to be either transposed into an International
Standard or withdrawn.
Attention is drawn to the possibility that some of the elements of this part of ISO/TS 11155 may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO/TS 11155-2 was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 7, Injection
equipment and filters for use on road vehicles.
ISO/TS 11155 consists of the following parts, under the general title Road vehicles — Air filters for passenger
compartments:
 Part 1: Test for particulate filtration
 Part 2: Test for gaseous filtration
Annex A forms a normative part of this part of ISO/TS 11155. Annexes B, C and D are for information only.
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TECHNICAL SPECIFICATION ISO/TS 11155-2:2002(E)

Road vehicles — Air filters for passenger compartments —
Part 2:
Test for gaseous filtration
1 Scope
This part of ISO/TS 11155 specifies a test comprising several methods for measuring the dynamic gas adsorption
of air filters in the passenger compartments of road vehicles. These laboratory test methods are applicable to air
filters that improve air quality by reducing concentrations of gaseous, odorous or hazardous components from
ambient or recirculated air, or both, in the vehicle cabin. They provide a means of measuring air pressure loss, as
well as gas and vapour removal characteristics.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of
this part of ISO/TS 11155. For dated references, subsequent amendments to, or revisions of, any of these
publications do not apply. However, parties to agreements based on this part of ISO/TS 11155 are encouraged to
investigate the possibility of applying the most recent editions of the normative documents indicated below. For
undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC
maintain registers of currently valid International Standards.
ISO/TS 11155-1, Road vehicles — Air filters for passenger compartments — Part 1: Test for particulate filtration
ISO 11841-1, Road vehicles and internal combustion engines — Filter vocabulary — Part 1: Definitions of filters
and filter components
ISO 11841-2, Road vehicles and internal combustion engines — Filter vocabulary — Part 2: Definitions of
characteristics of filters and their components
3 Terms and definitions
For the purposes of this part of ISO/TS 11155, the terms and definitions given in ISO 11841-1 and ISO 11841-2,
and the following apply.
3.1
test air flow rate
volume of air passing through the test duct per unit time
NOTE It is expressed in actual cubic metres per hour unit time.
3.2
pressure loss
difference in static pressure measured upstream and downstream of the filter at a specified flow rate
NOTE It is expressed in pascals.
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ISO/TS 11155-2:2002(E)
3.3
contaminant
unwanted constituent dispersed in air
3.4
concentration
mass quantity of one constituent dispersed in another
NOTE It is generally expressed as the mass of contaminant/volume air in milligrams per cubic metre or volume
contaminant/volume air in parts per million by volume. See annex D.
3.5
influent air
cleaned air used to dilute contaminants and produce the challenge gas
3.6
challenge gas
homogeneous mixture of influent air and contaminant used to challenge the filter
3.7
challenge gas concentration
ratio of the mass (or volume) of test contaminant per volume of influent air measured under specified conditions
NOTE It is expressed in milligrams per cubic metre or parts per million by volume. See annex D.
3.8
test gas mass
total mass of test contaminant (m ) to which the filter is exposed
T
NOTE It is expressed in milligrams.
3.9
influent concentration
C
1
homogeneous challenge gas concentration measured before (upstream of) the filter
NOTE It is expressed in milligrams per cubic metre or parts per million by volume. See annex D.
3.10
effluent concentration
C
2
homogeneous challenge gas concentration measured after (downstream of) the filter
NOTE It is expressed in milligrams per cubic metre or parts per million by volume. See annex D.
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ISO/TS 11155-2:2002(E)
3.11
efficiency [penetration]
relative comparison of the amount of contaminant removed or reduced by the filter compared to the amount
exposed to it, calculated as a percentage by
100CC−
()
12
E = (1)
C
1
where
E is efficiency
C is the influent concentration
1
C is the effluent concentration

2
NOTE 1 Percentage penetration = 100 % − percentage efficiency.
NOTE 2 Percentage breakthrough = 100 % − percentage efficiency.
3.11.1
1 min efficiency
efficiency measurement 1 min after time zero ( t )
0
3.11.2
2 min efficiency
efficiency measurement 2 min after t
0
3.11.3
5 min efficiency
efficiency measurement 5 min after t
0
3.12
time zero
t
0
calculated zero point based on the shape of the ramp-up curve of gas challenge breakthrough versus time
See clause 7 and annex B.
NOTE 1 Once this curve is obtained, the t point can be found by calculation. All efficiency or penetration data is calculated
0
from the designated t .
0
3.13
start of test time
t
start
time at which the challenge gas is introduced into the test system
3.14
lag time
t
lag
time difference between t and t
start 0
See annex B.
3.15
end of test time
t
f
time at which a user-specified efficiency (typically 5 %) or user-specified time is reached
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ISO/TS 11155-2:2002(E)
3.16
total test time
duration of exposure of the filter to the challenge gas, beginning at t
0
3.17
capacity
m
c
mass of contaminant removed from the challenge gas stream by the filter during the total test time
NOTE It is normally expressed in milligrams.
3.18
desorption
release of previously trapped contaminants from a test filter
4 Measurement accuracy
4.1 Flow rate monitors
The measurement devices are to be calibrated relative to the respective challenge or contaminant gases. Their
accuracy shall be within ± 3 % of the specified value.
4.2 Pressure monitors
The differential pressure shall be within ± 2 % of the measured value.
4.3 Temperature
Temperature shall be monitored to within ± 0,5 °C accuracy.
4.4 Relative humidity
Relative humidity shall be monitored to within ± 2 %.
4.5 Challenge gas measurement accuracy
Challenge gas measurement accuracy for n-butane, toluene and SO shall be ± 3 %.
2
5 General conditions
5.1 Conditioning of air
The temperature of the challenge gas mixture shall be 23 °C ± 3 °C and the relative humidity 50 % ± 2 %.
5.2 Cleanliness of influent air
The content of organic contaminants in the influent air must not exceed the equivalent of a volume fraction of
−6 1)
2 × 10 (parts per million by volume ) of total hydrocarbon. HEPA filtration is recommended for the removal of
particulate contaminants.

1) The unit "ppm", or a unit derived from it, is a deprecated unit, i.e. not accepted by the International System of Units, SI.
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ISO/TS 11155-2:2002(E)
5.3 Challenge gas concentration stability
Inlet challenge gas concentration shall be maintained to within ± 3 % of set concentration for the duration of the
test.
6 Test contaminants
6.1 Mandatory contaminants
Mandatory test contaminants are chosen either because their presence at high levels signifies deterioration in air
quality or because they provide useful indications of performance for certain types of purification systems.
Mandatory contaminants, purities and concentrations are specified in Table 1.
Table 1 — Test contaminants
Concentration
Test contaminant Minimum purity
Set point Conversion
b c
% parts per million by volume Factor ×
a
n-butane 99,5 80 ± 8 2,39
Toluene 99,5 80 ± 8 3,79
a
Included because it provides a useful and facile test for activated carbon-based adsorption systems. Butane could be of limited value for
systems that do not rely on activated carbon adsorption. In these cases, another test contaminant may be substituted.
b
See annex D for conversion to SI units.
c
Allows conversion to milligrams per cubic metre at 23 °C and a barometric pressure of 101 kPa (1,0 atm).

6.2 Optional contaminants
Tests using the optional contaminant are subject to agreement between customer and manufacturer.
Recommended contaminants, purities and concentrations are given in Table 2.
Table 2 — Optional test contaminant
Concentration
Test contaminant Minimum purity
Set point Conversion
b c
% parts per million by volume Factor ×

a
SO 99,5 30 ± 3 2,64
2
a
Included because it can be used to represent the family of acid gases in determining the performance of carbon-based adsorption
systems.
b
See annex D for conversion to SI units.
c
Allows conversion to milligrams per cubic metre at 23 °C and barometric pressure of 101 kPa (1,0 atm). (The unit for standard
atmosphere, “atm”, is a deprecated unit, i.e. not accepted by the International System of Units, SI.)
6.3 Other contaminants
See annex C for other contaminants. The use of other gases could be of interest for dedicated applications. Gases
of interest shall be agreed between customer and manufacturer.
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ISO/TS 11155-2:2002(E)
7 Test equipment
7.1 General layout
The test stand shall meet the performance requirements given in 7.2 to 7.7. An example of a test stand
configuration is given in annex A (see Figure A.1). All parts of the system which come into contact with the
challenge gas shall be chosen and designed such that they are chemically resistant and errors due to adsorptive
effects on part surfaces are minimized. The test stand shall include equipment or apparatus for conditioning the air
supply, flow measurement, pressure drop measurement, contaminant injection, sampling and sample analysis.
The test stand/equipment should preferably be operated in a sub-barometric pressure mode, i.e. with the
fan/blower placed downstream of the sample. This configuration prevents penetration of challenge gas into the
ambient atmosphere in case of equipment leaks. Furthermore, systematic errors due to the challenge gas
contacting the fan unit are excluded. Although operation in a sub-barometric pressure mode is preferred for these
reasons, a system operating in a positive pressure mode that meets the requirements of 7.2 to 7.7 is acceptable.
7.2 Test stand performance
The test stand shall be validated as part of the overall test system (stand and associated equipment) as given in
clause 11. Validation shall be performed whenever test conditions (e.g. flow rate) or test stand configuration (e.g.
mixing or fixture) are altered significantly. Test instruments shall be calibrated in accordance with the
manufacturer’s recommended practice and frequency.
7.3 Air supply
The influent air shall be conditioned and cleaned in accordance with 5.1 and 5.2. The system shall demonstrate the
ability to maintain these conditions over the period of time required to complete a filter evaluation. The system shall
be capable of delivering and maintaining a user-specified flow.
7.4 Test duct
In general, the test duct shall be designed so that adsorption of test contaminants on test stand surfaces is
minimized. The test duct is to be designed so that the challenge gas is fed evenly to the complete filter surface.
Punched sheets, static mixers or deflectors can be useful for this purpose. Mixing of the injected test contaminant
with the test duct’s air will require rigorous attention and validation. In general, a duct similar to that described in
ISO/TS 11155-1 (particulate) may be used to meet these specifications. However, those design details of the
ISO/TS 11155-1 layout that are specific to particle handling and measurement, and which do not influence the
handling and measurement of gases, are not obligatory for the test equipment.
7.5 Contaminant generation and supply
Test contaminants that are already gaseous under tes
...