ISO 5011:2000

INTERNATIONAL ISO
STANDARD 5011
Second edition
2000-12-01
Corrected and reprinted
2001-07-15
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 2000
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ii © ISO 2000 – All rights reserved

Contents Page
Foreword.v
1 Scope .1
2 Normative references .1
3 Terms, definitions, symbols and units .1
3.1 Terms and definitions .1
3.2 Symbols and units.3
4 Measurement accuracy and standard conditions.4
4.1 Measurement accuracy.4
4.2 Standard conditions .4
5 Test materials and test conditions.4
5.1 Test dust.4
5.2 Test oil for oil bath air cleaners.5
5.3 Absolute filter materials.5
5.4 Absolute filter mass .6
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
6.5 Capacity test.10
6.6 Filter element pressure collapse test .10
6.7 Variable air flow test.11
6.8 Presentation of data .11
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
7.6 Presentation of data .15
7.7 Scavenged air cleaner performance test .16
7.8 Precleaner performance test .17
7.9 Secondary element test procedure.18
8 Test procedure for industrial applications of oil bath air cleaners .19
8.1 General.19
8.2 Test equipment and conditions.19
8.3 Restriction and differential pressure test .20
8.4 Oil carry-over test .20
8.5 Full life efficiency and capacity test .21
8.6 Recovery test .21
8.7 Presentation of data .21
Annex A (normative) Explanation of restriction, differential pressure and pressure loss of an air
cleaner .22
Annex B (normative) Test equipment .24
Annex C (informative) Report sheet on performance testing of air cleaner equipment according to
ISO 5011 — Automotive application .33
Annex D (informative) Report sheet on performance testing of air cleaner equipment according to
ISO 5011 — Industrial application.34
Annex E (informative) Presentation of results — Air cleaner restriction/differential pressure versus
flow .35
Annex F (informative) Presentation of results — Air cleaner capacity.36
Annex G (normative) Airflow and resistance corrections to standard conditions.37
Bibliography .39
iv © ISO 2000 – All rights reserved

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.
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 International Standard may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights.
International Standard ISO 5011 was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee
SC 7, Injection equipment and filters for use on road vehicles.
This second edition cancels and replaces the first edition (ISO 5011:1988), which has been technically revised.
Annexes A, B and G form a normative part of this International Standard. Annexes C to F are for information only.
INTERNATIONAL STANDARD ISO 5011:2000(E)
Inlet air cleaning equipment for internal combustion engines
and compressors — Performance testing
1 Scope
This International Standard 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 effciency, dust capacity, and oil carry-over on oil bath air cleaners. This test code therefore deals with the
measurement of these parameters.
This International Standard is applicable to air cleaners used on internal combustion engines and compressors
generally used in automotive and industrial applications.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of
this International Standard. For dated references, subsequent amendments to, or revisions of, any of these
publications do not apply. However, parties to agreements based on this International Standard 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 5167-1, Measurement of fluid flow by means of pressure differential devices — Part 1: Orifice plates, nozzles
and Venturi tubes inserted in circular cross-section conduits running full.
ISO 12103-1, Road vehicles — Test dust for filter evaluation — Part 1: Arizona test dust.
3 Terms, definitions, symbols and units
3.1 Terms and definitions
For the purposes of this International Standard, the following terms and definitions apply.
3.1.1
air filter
air cleaner
device which removes particles suspended in the fresh charge as it is drawn into the engine
3.1.2
filter element
replaceable part of the air filter, consisting of the filter material and carrying frame
3.1.3
secondary element
air cleaner 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
3.1.4
unit under test
either a single air cleaner element or a complete air cleaner assembly
3.1.5
single-stage air cleaner
air cleaner which does not incorporate a separate precleaner
3.1.6
multistage air cleaner
air cleaner consisting of two or more stages, the first usually being a precleaner, followed by one or more filter
elements
NOTE If two elements are used, the first is called the primary element and the second one is called the secondary element.
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
3.1.8
test air flow
measure of the quantity of air drawn through the air cleaner outlet per unit time
NOTE 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 It maybeusedasthe testairflow.
3.1.10
scavenge air flow
measure of the quantity of air used to remove the collected dust from a precleaner
NOTE It is expressed as a percentage of the test air flow.
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 In the tests specified in this International Standard, a static pressure is measured by a manometer (usually a liquid
manometer) as a negative pressure difference against the atmospheric pressure and in the formulae this is treated as a positive
value.
3.1.12
restriction
static pressure measured immediately downstream of the unit under test
2 © ISO 2000 – All rights reserved

3.1.13
differential pressure
difference in static pressure measured immediately upstream and downstream of the unit under test
3.1.14
pressure loss
measure of the loss of energy caused by an air cleaner at the observed air flow rate
NOTE 1 It is expressed as the differential pressure corrected for any difference in the dynamic head at the measuring points.
NOTE 2 For further information, see annex A.
3.1.15
absolute filter
filter downstream of the unit under test to retain the contaminant passed by the unit under test
3.1.16
efficiency
ability of the air cleaner or the unit to remove contaminant under specified test conditions
3.1.17
capacity
quantity of contaminant removed by the unit under test 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, the occurrence of which signifies the end of the test
NOTE A test terminal condition may be, for example, any one of the following:
� the restriction or the differential pressure reaches a specified or agreed value;
� the dust-removing efficiency or some other performance parameter falls to a specified or agreed value;
� oil carry-over occurs;
� a dust pot becomes filled.
3.1.20
automotive application
air cleaner generally used for internal combustion engines in passenger cars
3.1.21
industrial application
air cleaner generally used for internal combustion engines in heavy-duty trucks, construction equipment and
agricultural tractors
3.2 Symbols and units
The following applied units, according to ISO 1000, are used.
Quantity Symbol Unit
Volume flow rate q m /min
V
Velocity v m/s
Density � kg/m
Mass flow rate q kg/min
m
Pressure p Pa
Restriction �p Pa
r
Differential pressure �p Pa
d
Pressure loss �p Pa
l
Mass m g
Time t s
4 Measurement accuracy and standard conditions
4.1 Measurement accuracy
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 of the actual value.
Measure the temperature to within 0,5 °C of the actual value.
Measure the mass to within 1 % of the actual value except where noted.
Measure the relative humidity (RH) with an accuracy of� 2 % RH.
Measure the barometric pressure to within 3 hPa.
The measurement equipment shall be calibrated at regular intervals to ensure the required accuracy.
4.2 Standard conditions
All airflow measurements shall be corrected to a standard condition of 20 °C at 1 013 hPa (1 013 mbar).
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 - A2 (ISO Fine) or ISO 12103 - A4 (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.
4 © ISO 2000 – All rights reserved

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 in a sealed container
for a minimum of 15 min. 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 may be found necessary to heat the dust prior to
being fed to the injector.
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:
� 85 mm /s for oil carry-over and restriction/differential pressure tests;
� 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 minimum density of
3 1)
9,5 kg/m . The fibre diameter shall be 0,76�mto 1,27�m and the moisture absorption shall 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 approx. 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 15 min before the first 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:
�m
A
E�� 100 % (1)
a
��mm�
AB
where
E is the absolute filter efficiency;
a
1) A suitable material is commercially available. Details may be obtained from the secretariat of ISO/TC 22 or from the ISO
Central Secretariat.
�m is the mass increase of upstream absolute filter;
A
�m is the mass increase of 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. 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 according to 5.5 may be drawn through the absolute filter for
15 min then the filter is weighed. Repeat this procedure until the mass has stabilized.
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 within the narrowest range of temperature and humidity
possible.
6 Test procedure for dry-type air cleaners for automotive applications
6.1 General
Performance tests shall be performed on a complete air cleaner assembly or on a single air cleaner element; tests
on a complete air cleaner assembly are preferred. The tests shall consist of an air flow restriction/differential
pressure test, an efficiency test and a capacity test. In addition, a pressure collapse test shall be performed on the
air filter element.
6.2 Test equipment
6.2.1 Typical arrangements to determine resistance to air flow, dust capacity, dust removal characteristics and
rupture collapse characteristics are shown in annex B, Figures B.1 and B.6 to B.11.
Use a dust feeder which when used with the dust injector in Figures B.2 and B.3 is capable of metering dust over
the range of delivery rates required. This dust feed system shall not change the primary particle size distribution of
the contaminant. The air feed pressure shall be 100 kPa minimum. The ISO heavy-duty injector pressure shall be
280 kPa minimum.
The dust feed system shall be validated as follows.
a) Charge the dust feeder with a pre-weighed amount of test dust.
b) Simultaneously start the dust feed system and timer.
c) At 5-min intervals, determine the mass of dust dispensed. Continue mass determinations of dust increments
for 30 min.
d) Adjust the dust feeder until the average delivery rate is within 5 % of the desired rate and the deviation in
delivery rate from the average is not more than 5 %.
6 © ISO 2000 – All rights reserved

6.2.2 Use a dust-transfer tube between the dust feeder and the injector of a size suitable to maintain dust
suspension.
6.2.3 Use the dust injector described in Table 1 and shown in Figures B.2 and B.3.
Table 1 — Recommended ISO dust injectors (see Figures B.2 and B.3)
Dust feed rate 0to26 26to45 > 45
g/min
ISO injector or
Injector type ISO injector ISO heavy-duty injector
ISO heavy-duty injector
The specified ISO injector has been shown to feed dust satisfactorily at rates up to 45 g/min. Where dust feed rates
greater than this are required, more than one injector will have to be used. It should be noted that the design of the
system feeding test dust to the injector may affect this maximum rate of dust feed. The maximum attainable dust
feed rate should therefore be determined prior to the dust feed/injector system being used for tests.
Injector nozzles are subject to natural erosion. Erosion may affect the distribution and delivery of test contaminant.
Therefore, it is recommended to use a design with replaceable parts.
6.2.4 Use an inlet tube conforming to Figure B.4. The dust injector and inlet tube shall be positioned in such a
way that there is no loss of dust.
6.2.5 Use a manometer or other differential pressure measuring device with the specified accuracy.
6.2.6 For air cleaner assembly testing, use a housing and set-up agreed upon by the manufacturer and user
conforming to Figure B.11. For air filter element testing, use a test set-up and shroud conforming to Figures B.1
and B.5 or an arrangement as shown in Figures B.6 or B.7. Where the test equipment is as shown in Figure B.6,
the dust is fed into the chamber and, to ensure that it does not adhere to the walls and is evenly distributed, dry
compressed air jets on flexible tubing should be provided in the test chamber, arranged so to agitate any dust that
settles out.
When using compressed air for agitating dust, care shall be taken not to eject any dust out of the champer. To
ensure that no dust is ejected from the chamber, a negative pressure should be maintained between the chamber
and the atmosphere.
6.2.7 Use an outlet tube conforming to Figure B.4. The cross-section shall be the same as the air cleaner outlet.
In the case of non-uniform flow conditions caused by special outlet tubes, special precautions may be required.
6.2.8 Use an air flow rate measuring system having the accuracy described in 4.1.
Validate the air flow rate measuring system. The air flow meter shall be of an acceptable design, such as a
calibrated orifice and manometer conforming to ISO 5167-1. The orifice unit shall be permanently marked such that
it can be identified after calibration. Corrections shall be made for variations in absolute pressure and temperature
at the meter inlet and the air flow rate shall be expressed in cubic metres per minute corrected to standard
conditions (see 4.2).
6.2.9 Use an air flow rate control system capable of maintaining the indicated flow rate to within 1 % of the
selected value during steady-state and variable air flow operation.
6.2.10 Use a blower/exhauster for inducing air flow through the system, which has adequate flow rate and
pressure characteristics for the filters to be tested. Pulsation of flow rate shall be so low that it is not measurable by
theflowratemeasuringsystem.
6.2.11 Grounding is required for all test apparatus to reduce the effects of static charges and to improve the
consistency of the test results. Grounding of metallic and non-metallic surfaces, housings, dust transport tubes,
injectors and associated hardware is recommended.
6.3 Restriction and differential pressure test
6.3.1 The purpose of this test is to determine the restriction/differential pressure/pressure loss across the unit
under test which will result when air is passed through under predetermined conditions. Airflow restriction or
differential pressure is measured with a clean filter element, or elements, at five equally spaced airflows of between
50 % and 150 % of the rated air flow, or as agreed upon between the user and manufacturer.
6.3.2 Condition the unit at the airflow rate at which the unit is tested for at least 15 min under temperature and
humidity conditions as specified in 5.5 until the mass has stabilized.
6.3.3 Set up the test stand as shown in Figures B.8 or B.9 and Figures B.14 or B.15. Seal all joints to prevent air
leaks. Connect pressure taps.
6.3.4 Measure and record the restriction and the differential pressure versus the flow rate at approximately 50 %,
75 %, 100 %, 125 % and 150 % of the rated air flow, or as agreed upon between the user and manufacturer.
6.3.5 Record the ambient temperature, pressure and relative humidity.
6.3.6 Correct the recorded restriction and differential pressure to standard conditions in accordance with
annex G.
6.3.7 For pressure loss determination, use the formula given in annex A.
6.3.8 Plot the results as shown in annex E or equivalent.
6.4 Efficiency test
6.4.1 Purpose
The purpose of this test is to determine the retention capabilities of the unit under test. This test can be conducted
with either constant or variable air flow and with coarse dust or fine test dust. If desired, efficiency tests can be
performed concurrently with capacity tests (see 6.5). Determination of the efficiency at constant test air flow can be
performed at the rated air flow or any percentage thereof, as agreed upon by the user and manufacturer.
Determination of efficiency at variable air flow can be performed using variable air flow cycle according to 6.7.
6.4.2 Types
Three types of efficiency tests can be performed, as follows:
a) full-life efficiency determined when the terminal condition, i.e. the terminating differential pressure, is reached;
b) incremental efficiency determined when, for example, 10 %, 25 % and 50 % of the terminating differential
pressure minus the initial differential pressure are reached;
c) initial efficiency determined after the addition of 20 g of contaminant or the number of grams numerically
equivalent to 6 times the air flow in cubic metres per minute, whichever is the greater.
6.4.3 Test procedure — Absolute filter method
6.4.3.1 Based on the test flow, calculate the test dust feed rate using a dust concentration of 1,0 g/m of air; in
3 3
special cases (e.g. small filters) 0,25 g/m or 0,5 g/m may be allowed.
6.4.3.2 Condition the unit under test according to 6.3.2, then measure and record the mass.
8 © ISO 2000 – All rights reserved

6.4.3.3 Weigh the absolute filter pad as specified in 5.4 and record mass before assembly within absolute filter
housing.
6.4.3.4 Set up test stand as shown in Figure B.11 for air cleaner assemblies, or as shown in Figure B.1, B.6 or
B.7 for air filter elements. Seal all joints to prevent air leakage.
6.4.3.5 Record the temperature and relative humidity.
6.4.3.6 Prepare the specified test dust according to 5.1 and weigh out the quantity required for test in a suitable
test container. For full-life efficiency tests, the quantity should be approximately 125 % of the estimated capacity of
the unit under test. Record the mass of the container and dust to the nearest 0,1 g.
6.4.3.7 Start the air flow through the test stand and stabilize at the test flow rate. Record the differential
pressure.
6.4.3.8 Load the dust feeder from the dust container and adjust the feed rate to inject dust at the concentration
calculated in 6.4.3.1. Reload the dust feeder from the dust container throughout the test as necessary.
6.4.3.9 At specified time intervals (a minimum of five points is recommended), record the differential pressure at
the test flow and the elapsed test time.
6.4.3.10 Continue the test until the specified terminal condition is reached.
6.4.3.11 Record the temperature and relative humidity.
6.4.3.12 The dust on the exterior surfaces of a cleaner assembly or any which may have settled in the test
chamber/ducting on the inlet side of a test element shall be collected carefully and transferred to the preweighed
dust container together with any dust remaining in the dust feeder.
6.4.3.13 Reweigh the dust container and subtract the result from the mass recorded in 6.4.3.6. The difference is
the mass of dust fed to the unit under test.
6.4.3.14 Carefully remove the unit under test without losing any dust. Note any evidence of seal leakage or
unusual conditions. Weigh the unit, in grams, to within 1 % of the actual value. The increase in mass of the unit
under test is this mass minus the mass determined in 6.4.3.2. In the full-life efficiency test [see 6.4.2 a)] this
increase in mass is the capacity of the unit under test.
6.4.3.15 Brush any observed dust on the downstream side of the test unit onto the absolute filter. Carefully
remove the absolute filter. Repeat step 6.4.3.3 and determine the difference in mass. This is the increase in mass
of the absolute filter.
6.4.3.16 Calculate the material balance, B, of the test dust. For the test to be valid, this value shall be within the
range 0,98 to 1,02:
��mm�
FU
B� (2)
m
D
where
�m is the increase in mass of the absolute filter;
F
�m is the increase in mass of the unit under test;
U
m is the total mass of dust fed.
D
6.4.3.17 Calculate the efficiency, E, by the following method:
�m
U
E��100 % (3)
��mm�
UF
where the symbols are as in equation (2).
6.4.4 Test procedure — Direct weighing method
The direct weighing method may be used for cumulative efficiency determination where the humidity can be
controlled to within� 1,0 % and the accuracy of the increase in mass of the filter determined to within 0,1 %.
Where a suitable large, accurate balance is available, it is permissible to use a direct weighing method of
assessing the performance of the unit under test. In such cases the air cleaner under test shall be tested according
to the procedure in 6.4.3 omitting the operations described in 6.4.3.3, 6.4.3.15, 6.4.3.16 and 6.4.3.17. Calculate the
efficiency, E,as follows:
�m
U
E��100 % (4)
m
D
where the symbols are as in equation (2).
The test report should indicate the method of efficiency determination used.
6.5 Capacity test
6.5.1 The purpose of this test is to determine the total mass gain of the unit under test at the terminating
condition. This test can be conducted with either constant or variable air flow and with coarse or fine test dust
contaminant. If desired, the capacity determination can be performed concurrently with the efficiency test (see 6.4).
6.5.2 Condition the unit according to 6.3.2. Perform the test as described in 6.4.3 or 6.4.4.
6.5.3 Assuming a constant ratio of elapsed time versus dust feed of the test unit, record the data and plot the
curve of restriction versus mass gain. Refer to 6.4.3.9 for restriction and time interval data. Determine the mass
gain values as follows:
t
I
��mm�� (5)
t UT
t
T
where
�m is the increase in mass at end of each time interval;
t
t is the total time at end of interval;
I
t is the total time at end of test;
T
�m is the total increase in mass of unit under test at end of test.
UT
6.5.4 In the case of the terminal condition being the restriction, it does not include the restriction added by the
dust mixing device and test shroud.
6.6 Filter element pressure collapse test
6.6.1 The purpose of this test is to determine the ability of an air filter element to withstand a specified differential
pressure and/or to determine the differential pressure at which collapse occurs.
10 © ISO 2000 – All rights reserved

6.6.2 Set up the test stand to perform the basic dust capacity test in accordance with Figure B.1, B.6, B.7 or
B.11. Either the element from the prior capacity or efficiency test or a new element can be used for this test.
6.6.3 Increase the air flow through the stand and, if necessary, feed dust at any convenient rate until the
specified differential pressure is reached or until element collapse is indicated by a decrease in differential pressure
or increase in air flow.
6.6.4 Record the maximum differential pressure attained, the reason for terminating the test, and the condition of
the element after test.
6.7 Variable air flow test
6.7.1 As an option to the constant air flow test, a variable air flow test can be carried out by using a variable air
flowcyclesimilar toFigure1.
6.7.2 In the case of oil bath air cleaners and large air cleaners (e.g. flow rate > 5 m /min), the duration of every
partial flow section may be 5 min instead of 1 min.
6.7.3 Based on the average test flow for the cycle being used, calculate the dust feed rate as in 6.4.3.1. The dust
feed rate should remain constant.
6.7.4 All differential pressure drop determinations shall be made at maximum air flow.
6.7.5 Perform tests using variable air flow in place of the constant air flow, however, with the following changes:
� after the end of each cycle the differential pressure shall be determined at the maximum flow; and
� the efficiency shall be determined at least after three cycles if the duration of partial flow section is 1 min and
after every cycle if the duration of partial flow section is 5 min, and after the end of test.
Figure 1 — Typical variable flow cycle (average flow 60 %)
6.8 Presentation of data
For presentation of data, use annexes C, E and F or equivalent.
7 Test procedure for dry-type air cleaners for industrial applications
7.1 General
Performance tests shall be performed on a complete air cleaner including precleaner, primary element, and
secondary element, if normally provided. The tests shall consist of an airflow restriction/differential pressure test, an
initial efficiency test, and a combined efficiency and dust capacity test.
It is difficult, if not impossible, to select a test dust size distribution and concentration which will be representative of
all service conditions. Therefore, based on primarily practical considerations, the different types of air cleaners
have been classified as to their most probable service conditions, and the test dust grade and concentration
selected accordingly from Table 2.
Table 2 — Test dust and concentration
a
Air cleaner type Test dust Concentration
Single stage Coarse or fine 1 g/m
Multistage Coarse or fine 2 g/m
a
In accordance with ISO 12103-1. See 5.11.
7.2 Test equipment
7.2.1 Typical test arrangements are shown in Figures B.12, B.14 and B.15.
7.2.2 The dust feeding system shall be the same as described in 6.2.1.
7.2.3 The dust transfer tube shall be the same as described in 6.2.2. Concerning the dust feed rate, see also
Table 1.
7.2.4 Tubular air cleaner inlet: the cross-sectional area of the upstream piezometer tube shall be the same as the
air cleaner inlet (see Figure B.4).
7.2.5 Rectangular or open face inlet: the same as 7.2.4 except the overall length and placement of the
piezometer shall be 24 and 16 times the hydraulic radius respectively (hydraulic radius = area divided through
perimeter).
7.2.6 The peripheral air inlet or stack type precleaners shall be tested in a chamber which ensures the even
distribution and delivery of test dust to the inlet of the unit. Care should be taken in the design of the chamber to
ensure that all the test dust is fed to the filter. If dust settling occurs, then compressed air jets may be used to
re-entrain the test dust. Typical examples of chambers are shown in Figure B.13.
When using compressed air for agitating dust, care should be taken not to eject dust out of the chamber. To ensure
that no dust is ejected, a negative pressure should be maintained between the chamber interior and the
atmosphere.
7.2.7 The outlet downstream piezometer tube shall be as shown in Figure B.4. The inside diameter of the outlet
downstream piezometer tube shall be the same as the air cleaner outlet tube. In the case of non-uniform flow
conditions caused by special outlet tubes, special precautions may be required.
7.2.8 The absolute filter shall comprise the material specified in 5.3.
7.2.9 Use an air flow measuring system as described in 6.2.8, an air flow control system as described in 6.2.9
and a blower/exhauster as described in 6.2.10.
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7.2.10 Grounding is required of all test apparatus to reduce the effects of static charges and to improve
consistency of test results. Grounding of metallic and non-metallic surfaces, housings, dust transport tubes,
injectors and associated hardware is recommended.
7.3 Restriction and differential pressure test
Test shall be performed according to 6.3.
7.4 Initial efficiency test procedure — Absolute filter method
7.4.1 Condition the unit to the air flow at which the unit is tested for at least 15 min under the temperature and
humidity conditions specified in 5.5.
If desired, conditioning of the absolute filter pad and air cleaner can be performed concurrently.
7.4.2 Weigh the absolute filter pad as specified in 5.4 and record the mass before assembly in the absolute filter
housing.
7.4.3 Prepare the test dust according to 5.1.1 and weigh out a quantity equal to 11 g/m of the primary element
media area. Place the preweighed dust in the dust feeder.
7.4.4 If it is practicable, weigh the complete unit under test.
7.4.5 Weigh the dust feed system with the dust and record the mass.
7.4.6 Set up the air cleaner as shown in Figure B.12 or B.13, sealing all connections to prevent air leakage, and
maintain the air flow at the test flow rate.
7.4.7 Start the dust feeder and adjust the feed rate to maintain continuous injection of the complete quantity of
test dust over a period of 30 min.
7.4.8 Record the temperature and relative humidity.
7.4.9 Brush any observed dust on the downstream side of the test unit onto the absolute filter. Carefully remove
and reweigh the absolute filter pad as in 5.4. Calculate the increase in mass by comparison with the mass recorded
in 7.4.2.
7.4.10 Collect all dust which has settled on the exterior surface, inlet ducting or test chamber, or the inlet side of
the test unit and transfer this dust to the dust feed system.
7.4.11 Reweigh the dust feed system to within 1 % of the actual value, and calculate the mass of dust injected into
the test cleaner by comparison with the initial mass of the dust feed system from 7.4.5.
7.4.12 If it is practicable, reweigh the complete unit under test.
7.4.13 Calculate the initial efficiency, E , as follows:
i
mm��
DF
E��100 % (6)
i
m
D
where the symbols are as in equation (2).
7.4.14 If it was practicable to weigh and reweigh the complete unit under test, the efficiency may be calculated
from equation (3) in 6.4.3.17. Validation of the test shall be carried out according to 6.4.3.16.
7.5 Full-life efficiency and capacity test
7.5.1 Air cleaner dust capacity
Air cleaner dust capacity is a function of air cleaner size, airflow test, terminal condition and grade of test dust
employed. To permit a comparison between different air cleaners, the dust capacity is, therefore, determined at test
air flow to the specified terminal condition with four intermediate points. In the absence of such a specification, a
restriction of 6 kPa (60 mbar) should be used as the terminal condition.
In the case of the terminating condition being the restriction, it does not include the restriction added by the dust
mixing duct and test shroud. The test can be conducted with either constant or variable air flow according to 6.7.
7.5.2 Test procedure — Absolute filter method
7.5.2.1 Condition the unit to the air flow at which the unit is tested for at least 15 min unde
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