Particulate air filters for general ventilation - Determination of the filtration performance

This European Standard refers to particulate air filters for general ventilation. These filters are classified according to their performance as measured in this test procedure.
This European Standard contains requirements to be met by particulate air filters. It describes testing methods and the test rig for measuring filter performance.
In order to obtain results for comparison and classification purposes, particulate air filters shall be tested against two synthetic aerosols, a fine aerosol for measurement of filtration efficiency as a function of particle size within a particle size range 0,2 m to 3,0 m, and a coarse one for obtaining information about test dust capacity and, in the case of coarse filters, filtration efficiency with respect to coarse loading dust (arrestance).
This European Standard applies to air filters having an initial efficiency of less than 98 % with respect to 0,4 µm particles. Filters shall be tested at an air flow rate between 0,24 m3/s  (850 m3/h) and 1,5 m3/s (5400 m3/h).
The performance results obtained in accordance with this standard cannot by themselves be quantitatively applied to predict performance in service with regard to efficiency and lifetime. Other factors influencing performance to be taken into account are described in Annex A (informative).

Partikel-Luftfilter für die allgemeine Raumlufttechnik - Bestimmung der Filterleistung

Diese Europäische Norm gilt für Partikel-Luftfilter für die allgemeine Raumlufttechnik. Diese Filter werden entsprechend ihrer Leistung klassifiziert, die nach diesem Prüfverfahren gemessen wird.
Diese Europäische Norm enthält Anforderungen für Partikel-Luftfilter. Sie beschreibt Prüfverfahren und den Prüfstand zur Messung der Filterleistung.
Um Ergebnisse zu Vergleichs- und Klassifizierungszwecken zu erhalten, müssen Partikel-Luftfilter mit zwei synthetischen Aerosolen geprüft werden, und zwar mit einem feinen Aerosol zur Messung des Wirkungs-grades in Abhängigkeit von der Partikelgröße in einem Partikelgrößenbereich von 0,2 µm bis 3,0 µm und einem groben Aerosol, um Informationen über die Staubspeicherfähigkeit und bei Grobstaubfiltern auch über den Abscheidegrad hinsichtlich groben Staubes (Abscheidung) zu erhalten.
Diese Europäische Norm gilt für Luftfilter, die mit einem Volumenstrom im Bereich von 0,24 m3/s (850 m3/h) bis 1,5 m3/s (5400 m3/h) geprüft werden müssen und deren Anfangswirkungsgrad (mit feinem Aerosol) für Partikel von 0,4 µm geringer als 98 % ist.
Die gemäß dieser Norm erhaltenen Leistungsergebnisse können nicht unmittelbar zur quantitativen Vorher-sage von Wirkungsgrad und Lebensdauer für den Anwendungsfall des Filters benutzt werden. Andere sich auf die Leistung auswirkende Faktoren, die berücksichtigt werden müssen, werden in Anhang A (normativ) und Anhang B (informativ) beschrieben.

Filtres à air de ventilation générale pour l'élimination des particules - Détermination des performances de filtration

La présente Norme européenne traite des filtres à air à particules pour la ventilation générale. Ces filtres sont
classés selon leur performance, mesurée suivant le présent mode opératoire d'essai.
La présente Norme européenne renferme les exigences que doivent remplir les filtres à air à particules. Elle
décrit des méthodes d'essai ainsi que le banc d'essai à utiliser pour mesurer la performance des filtres.
De façon à obtenir des résultats pour la comparaison et la classification, les filtres à particules doivent être
soumis à essai par rapport à deux aérosols synthétiques, un aérosol fin pour mesurer l'efficacité de filtration
en fonction de la taille des particules dans une plage de dimensions de particules de 0,2 μm à 3,0 μm, et un
aérosol grossier pour obtenir des informations sur la capacité de colmatage et, dans le cas des filtres
grossiers, l'efficacité de filtration vis-à-vis de la poussière de colmatage grossière (rendement gravimétrique).
La présente Norme européenne s'applique aux filtres à air ayant une efficacité initiale inférieure à 98 % pour
des particules de 0,4 μm. Les filtres doivent être soumis à essai à un débit d'air compris entre
0,24 m3/s (850 m3/h) et 1,5 m3/s (5 400 m3/h).
Les résultats de performance obtenus à l'aide de la présente norme ne peuvent pas être utilisés
quantitativement pour prévoir la performance en service, en ce qui concerne l'efficacité et la durée de vie. Les
autres facteurs ayant une influence sur la performance et devant être pris en compte sont décrits dans
l'Annexe A (informative).

Zračni filtri za delce pri splošnem prezračevanju - Ugotavljanje učinkovitosti filtracije

Ta evropski standard zadeva zračne filtre za delce pri splošnem prezračevanju . Ti filtri so razvrščeni glede na zmogljivost, ugotovljeno na podlagi tega preskusnega postopka. Ta evropski standard vsebuje zahteve, ki jih morajo izpolnjevati zračni filtri za delce. Opisuje preskusne metode in preskuševališče za merjenje zmogljivosti filtrov. Da bi se pridobili rezultati za namene primerjave in razvrstitve, je treba zračne filtre za delce preskusiti na podlagi dveh sintetičnih aerosolov, in sicer finega aerosola za merjenje učinkovitosti filtracije glede na velikost delcev, pri čemer je razpon velikosti med 0,2 μm in 3,0 μm, ter grobega aerosola za pridobitev informacij o zmogljivosti zajemanja prahu, v primeru grobih filtrov pa o učinkovitosti filtracije v zvezi z odstranjevanjem grobih delcev prahu iz zraka. Ta evropski standard velja za zračne filtre, katerih začetna učinkovitost v zvezi z delci velikosti 0,4 μm je manj kot 98 %. Filtre je treba preskusiti pri stopnji pretoka zraka med 0,24 m3/s (850 m3/h) in 1,5 m3/s (5400 m3/h). Rezultatov glede zmogljivosti, pridobljenih v skladu s tem standardom, ni mogoče samih po sebi kvantitativno uporabiti za predvidevanje zmogljivosti med obratovanjem, in sicer v zvezi z učinkovitostjo in življenjsko dobo. Drugi dejavniki, ki vplivajo na zmogljivost in ki jih je treba upoštevati, so opisani v dodatku A (informativnem).

General Information

Status
Withdrawn
Publication Date
10-Apr-2012
Withdrawal Date
13-Dec-2016
Current Stage
9960 - Withdrawal effective - Withdrawal
Completion Date
14-Dec-2016

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SLOVENSKI STANDARD
SIST EN 779:2012
01-september-2012
1DGRPHãþD
SIST EN 779:2004
=UDþQLILOWUL]DGHOFHSULVSORãQHPSUH]UDþHYDQMX8JRWDYOMDQMHXþLQNRYLWRVWL
ILOWUDFLMH

Particulate air filters for general ventilation - Determination of the filtration performance

Partikel-Luftfilter für die allgemeine Raumlufttechnik - Bestimmung der Filterleistung

Filtres à air de ventilation générale pour l''élimination des particules - Exigences, essais,

marquage
Ta slovenski standard je istoveten z: EN 779:2012
ICS:
91.140.30 3UH]UDþHYDOQLLQNOLPDWVNL Ventilation and air-
VLVWHPL conditioning
SIST EN 779:2012 en,fr

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 779:2012
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SIST EN 779:2012
EUROPEAN STANDARD
EN 779
NORME EUROPÉENNE
EUROPÄISCHE NORM
April 2012
ICS 91.140.30 Supersedes EN 779:2002
English Version
Particulate air filters for general ventilation - Determination of the
filtration performance

Filtres à air de ventilation générale pour l'élimination des Partikel-Luftfilter für die allgemeine Raumlufttechnik -

particules - Détermination des performances de filtration Bestimmung der Filterleistung

This European Standard was approved by CEN on 14 April 2011.

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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland,

Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: Avenue Marnix 17, B-1000 Brussels

© 2012 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 779:2012: E

worldwide for CEN national Members.
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SIST EN 779:2012
EN 779:2012 (E)
Contents

Foreword ...................................................................................................................................................................... 4

Introduction ................................................................................................................................................................. 5

1 Scope .............................................................................................................................................................. 7

2 Normative references .................................................................................................................................... 7

3 Terms and definitions ................................................................................................................................... 7

4 Symbols and abbreviated terms ................................................................................................................ 11

5 Requirements ............................................................................................................................................... 12

6 Classification ................................................................................................................................................ 14

7 Test rig and equipment ............................................................................................................................... 15

7.1 Test conditions ............................................................................................................................................ 15

7.2 Test rig .......................................................................................................................................................... 15

7.3 Aerosol generation – DEHS Test Aerosol ................................................................................................. 17

7.4 Aerosol sampling system ........................................................................................................................... 18

7.5 Flow measurement ...................................................................................................................................... 19

7.6 Particle counter ............................................................................................................................................ 19

7.7 Differential pressure measuring equipment ............................................................................................. 19

7.8 Dust feeder ................................................................................................................................................... 19

8 Qualification of test rig and apparatus ...................................................................................................... 23

8.1 Air velocity uniformity in the test duct ...................................................................................................... 23

8.2 Aerosol uniformity in the test duct ............................................................................................................ 23

8.3 Particle counter sizing accuracy ................................................................................................................ 24

8.4 Particle counter zero test ............................................................................................................................ 25

8.5 Particle counter overload test .................................................................................................................... 25

8.6 100 % efficiency test .................................................................................................................................... 25

8.7 Zero % efficiency test .................................................................................................................................. 25

8.8 Aerosol generator response time .............................................................................................................. 26

8.9 Pressure equipment calibration ................................................................................................................. 26

8.10 Pressure drop checking .............................................................................................................................. 26

8.11 Dust feeder air flow rate .............................................................................................................................. 26

8.12 Summary of qualification requirements .................................................................................................... 27

8.13 Apparatus maintenance .............................................................................................................................. 28

9 Test materials ............................................................................................................................................... 28

9.1 Test air - cleanliness, temperature and humidity ..................................................................................... 28

9.2 Test aerosol .................................................................................................................................................. 28

9.3 Loading dust ................................................................................................................................................ 29

9.4 Final filter ...................................................................................................................................................... 29

10 Test procedure for the filter ........................................................................................................................ 30

10.1 Preparation of filter to be tested ................................................................................................................ 30

10.2 Initial pressure drop .................................................................................................................................... 30

10.3 Initial efficiency ............................................................................................................................................ 30

10.3.1 General .......................................................................................................................................................... 30

10.3.2 Efficiency measurement ............................................................................................................................. 30

10.4 Dust loading ................................................................................................................................................. 31

10.4.1 Dust loading procedure .............................................................................................................................. 31

10.4.2 Arrestance .................................................................................................................................................... 32

10.4.3 Efficiency ...................................................................................................................................................... 33

10.4.4 Average efficiency ....................................................................................................................................... 33

10.4.5 Test dust capacity........................................................................................................................................ 33

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SIST EN 779:2012
EN 779:2012 (E)

11 Test method for discharging of filter material .......................................................................................... 34

11.1 General.......................................................................................................................................................... 34

11.2 Equipment .................................................................................................................................................... 34

11.3 Preparation of test samples ....................................................................................................................... 35

11.4 Measurement of the filter medium efficiency ........................................................................................... 35

11.4.1 General.......................................................................................................................................................... 35

11.4.2 Isopropanol test ........................................................................................................................................... 35

11.4.3 Expression of results .................................................................................................................................. 36

11.5 Report ........................................................................................................................................................... 36

12 Uncertainty calculation of the test results ................................................................................................ 37

13 Reporting ...................................................................................................................................................... 38

13.1 General.......................................................................................................................................................... 38

13.2 Interpretation of test reports ...................................................................................................................... 39

13.3 Summary ...................................................................................................................................................... 39

13.4 Efficiency ...................................................................................................................................................... 41

13.5 Pressure drop and air flow rate .................................................................................................................. 41

13.6 Arrestance and test dust capacity ............................................................................................................. 42

13.7 Marking ......................................................................................................................................................... 42

Annex A (informative) Shedding from filters .......................................................................................................... 51

A.1 General.......................................................................................................................................................... 51

A.2 Shedding ...................................................................................................................................................... 51

A.2.1 Particle bounce ............................................................................................................................................ 51

A.2.2 Release of fibres or particulate matter from filter material ..................................................................... 51

A.2.3 Re-entrainment of particles ........................................................................................................................ 51

A.3 Testing .......................................................................................................................................................... 52

A.4 References ................................................................................................................................................... 52

Annex B (informative) Commentary ........................................................................................................................ 53

B.1 General.......................................................................................................................................................... 53

B.2 Classification ............................................................................................................................................... 53

B.3 Test ................................................................................................................................................................ 53

B.3.1 Test aerosol .................................................................................................................................................. 53

B.3.2 Loading dust ................................................................................................................................................ 54

B.3.3 Distribution and sampling of aerosols ...................................................................................................... 54

B.3.4 Particle counter characteristics ................................................................................................................. 54

B.3.5 Flat sheet test ............................................................................................................................................... 54

B.4 Filtration characteristics ............................................................................................................................. 55

B.4.1 General.......................................................................................................................................................... 55

B.4.2 Pressure drop .............................................................................................................................................. 55

B.4.3 Discharged efficiency.................................................................................................................................. 55

Annex C (informative) Pressure drop calculation .................................................................................................. 56

Annex D (informative) Example of a completed test report .................................................................................. 58

D.1 Example of test reports ............................................................................................................................... 58

D.2 Examples of calculations ............................................................................................................................ 66

D.3 Final results at 450 Pa ................................................................................................................................. 69

Bibliography .............................................................................................................................................................. 70

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SIST EN 779:2012
EN 779:2012 (E)
Foreword

This document (EN 779:2012) has been prepared 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 October 2012, and conflicting national standards shall be withdrawn at the latest

by October 2012.

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights.

CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.

This document supersedes EN 779:2002.

EN 779:2012 is based on the test method according to EN 779:2002. It contains extensive test rig qualification

procedures together with procedures which give some information regarding the real life behaviour of particulate air

filters (see ”Introduction”).
Annexes A to D are informative.

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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,

Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden,

Switzerland, Turkey and the United Kingdom.
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SIST EN 779:2012
EN 779:2012 (E)
Introduction
General

The procedures described in this standard have been developed from those given in EN 779:2002. The basic

design of test rig given in EN 779:2002 is retained. A challenge aerosol of DEHS (or equivalent) is dispersed evenly

across the duct upstream of the filter being tested. Representative upstream and downstream air samples are

analysed by an optical particle counter (OPC) to provide filter particle size efficiency data.

Classification

The EN 779:2002 classification system (comprising groups F and G filters) has been changed to three groups (F-,

M- and G-filters).

Filters found to have an average efficiency value of less then 40 % of 0,4 µm particles will be allocated to group G

and the efficiency reported as “< 40 %”. The classification of G filters (G1 - G4) is based on their average

arrestance with the loading dust.

Filters found to have an average efficiency value from 40 % to less than 80 % of 0,4 µm particles will be allocated

to group M (M5, M6) and the classification is based on their average efficiency (0,4 µm). The filter classes F5 and

F6 have changed to M5 and M6, but with same requirements, as in the old classification system.

Filters found to have an average efficiency of 80 % or more of 0,4 µm particles will be allocated to group F (F7-F9)

and the classification is based on their average efficiency (0,4 µm) as in the old system and the minimum efficiency

during the test.
Test aerosol

A challenge aerosol of DEHS (or equivalent) was chosen for the efficiency test for the following reasons:

 Experience has already been gained by users of EN 779:2002 and Eurovent 4/9 test method so that much

suitable equipment already exists.

 Liquid aerosols is easy to generate in the concentrations, size range and degree of consistency required.

 Undiluted DEHS is used to give a non charged aerosol.

 Spherical latex particles are used to calibrate particle counters. The determination of the particle size of

spherical liquid particles using optical particle counters is more accurate than would be the case with solid

particles of non-spherical salt and test dusts.
Filtration characteristics

Initiatives to address the potential problems of particle re-entrainment and shedding from filters have been included

in Annex A.

In an ideal filtration process, each particle would be permanently arrested at the first contact with a filter fibre, but

incoming particles may impact on a captured particle and dislodge it into the air stream. Fibres or particles from the

filter itself could also be released, due to mechanical forces. From the user’s point of view it might be important to

know this, but such behaviour would probably not be detected by a particle counter system according to this

standard.

Certain types of filter media rely on electrostatic effects to achieve high efficiencies at low resistance to air flow.

Exposure to some types of challenge, such as combustion particles in normal atmospheric air or oil mist, may

neutralise such charges with the result that filter performance suffers. It is important that the users are aware of the

potential for performance degradation when loss of charge occurs. It is also important that means be available for

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SIST EN 779:2012
EN 779:2012 (E)

identifying cases where the potential exists. The discharge test procedure described provides techniques for

identifying this type of behaviour. This procedure is used to determine whether the filter efficiency is dependent on

the electrostatic removal mechanism and to provide quantitative information about the importance of the

electrostatic removal.
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SIST EN 779:2012
EN 779:2012 (E)
1 Scope

This European Standard refers to particulate air filters for general ventilation. These filters are classified according

to their performance as measured in this test procedure.

This European Standard contains requirements to be met by particulate air filters. It describes testing methods and

the test rig for measuring filter performance.

In order to obtain results for comparison and classification purposes, particulate air filters shall be tested against

two synthetic aerosols, a fine aerosol for measurement of filtration efficiency as a function of particle size within a

particle size range 0,2 µm to 3,0 µm, and a coarse one for obtaining information about test dust capacity and, in the

case of coarse filters, filtration efficiency with respect to coarse loading dust (arrestance).

This European Standard applies to air filters having an initial efficiency of less than 98 % with respect to 0,4 µm

3 3 3 3

particles. Filters shall be tested at an air flow rate between 0,24 m /s (850 m /h) and 1,5 m /s (5400 m /h).

The performance results obtained in accordance with this standard cannot by themselves be quantitatively applied

to predict performance in service with regard to efficiency and lifetime. Other factors influencing performance to be

taken into account are described in Annex A (informative).
2 Normative references

The following documents, in whole or in part, are normatively referenced in this document and are indispensable for

its application. For dated references, only the edition cited applies. For undated references, the latest edition of the

referenced document (including any amendments) applies.

EN ISO 5167-1:2003, 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 5167-1:2003)

ISO 2854:1976, Statistical interpretation of data  Techniques of estimation and tests relating to means and

variances

ISO 12103-1:1997, Road vehicles  Test dust for filter evaluation  Part 1: Arizona test dust

3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
arrestance
weighed (mass) removal of loading dust
3.2
average arrestance - A

ratio of the total amount of loading dust retained by the filter to the total amount of dust fed up to final test pressure

drop
Note 1 to entry: Average arrestance is used for classification of G-filters.
3.3
average efficiency - E

weighted average of the efficiencies of 0,4 µm particles for the different specified dust loading levels up to final test

pressure drop

Note 1 to entry: Average efficiency is used for classification of M and F-filters.

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SIST EN 779:2012
EN 779:2012 (E)
3.4
average efficiency - E
i,j
average efficiency for a size range ”i” at different dust loading intervals ”j”
3.5
average discharged efficiency - E
D,i
average efficiency for a size range ”i” after discharging filter samples
3.6
average untreated efficiency - E
U,i
average efficiency for a size range ”i” of untreated filter samples
3.7
charged filter
filter which is electrostatically charged or polarised
3.8
coarse filter
filter classified in one of the classes G1 to G4
3.9
counting rate
number of counting events per unit of time
3.10
DEHS
liquid (DiEthylHexylSebacate) for generating the test aerosol
3.11
discharged efficiency
efficiency of filter media after having been discharged by isopropanol
3.12
test dust capacity
amount of loading dust retained by the filter up to final test pressure drop
3.13
efficiency

see initial efficiency, discharged efficiency, minimum efficiency and average efficiencies

3.14
face area

area of the inside section of the test duct immediately upstream of the filter under test

Note 1 to entry: Nominal values 0,61 m × 0,61 m = 0,372 m .
3.15
face velocity
air flow rate divided by the face area
3.16
final filter
air filter used to collect the loading dust passing the filter under test
3.17
final pressure drop - recommended

maximum operating pressure drop of the filter as recommended by the manufacturer at rated air flow

3.18
final test pressure drop

pressure drop up to which the filtration performance is measured for classification purposes

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SIST EN 779:2012
EN 779:2012 (E)
3.19
fine filter
filter classified in one of the classes F7 to F9
3.20
HEPA filter

High Efficiency Particulate Air filter, classes H13 to H14 according to EN 1822-1

3.21
initial arrestance
arrestance of the first 30 g loading dust increment
3.22
initial efficiency
efficiency of the clean filter operating at the test air flow rate
Note 1 to entry: For each size range of selected particles.
3.23
initial pressure drop
pressure drop of the clean filter operating at its test air flow rate
3.24
isokinetic sampling

sampling of the air within a duct such the probe inlet air velocity is the same as the velocity in the duct at the

sampling point
3.25
loading dust
same as synthetic dust
3.26
mean diameter
geometric average of the size range diameter
3.27
media velocity
air flow rate divided by the net effective filtering area
Note 1 to entry: Expressed in m/s to an accuracy of three significant figures.
3.28
medium filter
filter classified in one of the classes M5 or M6
3.29
minimum efficiency

lowest efficiency among the discharged efficiency, initial efficiency and the lowest efficiency throughout the loading

procedure of the test
Note 1 to entry: Minimum efficiency is used for classification of F-filters.
3.30
net effective filtering area
area of filter medium in the filter which collects dust
3.31
particle bounce

describes the behaviour of particles that impinge on the filter without being retained

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SIST EN 779:2012
EN 779:2012 (E)
3.32
particle size
equivalent optical diameter of a particle
3.33
particle number concentration
number of particles per unit of volume of the test air
3.34
penetration
ratio of the particle concentration downstream to upstream of the filter
3.35
re-entrainment
releasing to the air flow of particles previously collected on the filter
3.36
shedding

releasing to the air flow of particles due to particle bounce and re-entrainment effects, and to the release of fibres or

particul
...

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