EN 15051-2:2025
(Main)Workplace exposure - Measurement of the dustiness of bulk materials - Part 2: Rotating drum method
Workplace exposure - Measurement of the dustiness of bulk materials - Part 2: Rotating drum method
This document specifies the rotating drum test apparatus and associated test method for the reproducible production of dust from a bulk material under standard conditions, and the measurement of the inhalable, thoracic and respirable dustiness mass fractions, with reference to existing European standards, where relevant (see Clause 6).
This method is suitable for general bulk material handling processes, including all those processes where the bulk material is dropped, or can be dropped. It differs from the continuous drop method presented in FprEN 15051-3:2025 [4]. In FprEN 15051-2:2025 the same bulk material is repeatedly dropped, whilst in FprEN 15051-3:2025, the bulk material is dropped only once, but continuously.
Furthermore, this document specifies the environmental conditions, the sample handling and analytical procedures, and the method of calculating and presenting the results. A categorization scheme for dustiness is specified, to provide a standardized way to express and communicate the results to users of the bulk materials.
This document is applicable to powdered, granular or pelletized bulk materials. A standard sample volume is used.
This document does not apply to test the dust released when solid bulk materials are mechanically reduced (e.g. cut, crushed).
Exposition am Arbeitsplatz - Messung des Staubungsverhaltens von Schüttgütern - Teil 2: Verfahren mit rotierender Trommel
Dieses Dokument legt die Prüfeinrichtung sowie das entsprechende Prüfverfahren mit rotierender Trommel fest, die bei der reproduzierbaren Erzeugung von Staub aus einem Schüttgut unter Normbedingungen verwendet werden; außerdem wird die Messung der Massenanteile an einatembarem, thorakalem und alveolengängigem Staub, gegebenenfalls unter Verweisung auf bestehende Europäische Normen (siehe Abschnitt 6), festgelegt.
Dieses Verfahren ist für allgemeine Handhabungsprozesse von Schüttgütern geeignet, einschließlich all jener Prozesse, bei denen das Schüttgut herabfällt oder herabfallen kann. Es unterscheidet sich von dem in EN 15051-3:2025 [4] vorgestellten Verfahren mit kontinuierlichem Fall. In EN 15051-2:2025 fällt dasselbe Schüttgut wiederholt herab, während das Schüttgut in EN 15051-3:2025 nur einmal, jedoch kontinuierlich, fällt.
Ferner legt dieses Dokument die Umgebungsbedingungen, den Umgang mit den Proben und die Analyseverfahren sowie die Verfahren zur Berechnung und Darstellung der Ergebnisse fest. Um eine genormte Grundlage für die Angabe und Weiterleitung der Ergebnisse an die Anwender von Schüttgütern zu schaffen, wird ein Kategorisierungssystem für das Staubungsverhalten festgelegt.
Dieses Dokument ist anwendbar für pulverförmige, granulierte oder pelletierte Schüttgüter. Es wird eine Probe mit einem genormten Volumen verwendet.
Dieses Dokument ist nicht für die Prüfung von Staub, der bei der mechanischen Zerkleinerung fester Schüttgüter (z. B. beim Schneiden, Brechen) freigesetzt wird, anwendbar.
Exposition sur les lieux de travail - Mesurage du pouvoir de resuspension des matériaux pulvérulents en vrac - Partie 2 : Méthode du tambour rotatif
Le présent document spécifie l'appareillage d'essai du tambour rotatif et la méthode d'essai associée à utiliser pour produire des poussières de manière reproductible à partir d'un matériau en vrac, dans des conditions normalisées, ainsi que les mesures des fractions massiques des poussières inhalables, thoraciques et alvéolaires, en référence aux Normes européennes existantes, s'il y a lieu (voir Article 6).
Cette méthode est adaptée aux processus de manipulation des matériaux en vrac en général, notamment à tous les processus impliquant ou pouvant impliquer la chute de matériaux en vrac. Elle se différencie de la méthode de la chute continue présentée dans l'EN 15051-3 [4]. Dans l'EN 15051‑2, le même matériau en vrac tombe de manière répétée, alors que dans l'EN 15051-3, le matériau en vrac tombe une seule fois, mais en continu.
Par ailleurs, le présent document spécifie les conditions ambiantes, les méthodes de manipulation et d'analyse des échantillons ainsi que la méthode de calcul et d'expression des résultats. Un schéma de classification du pouvoir de resuspension est spécifié afin de fournir une méthode normalisée pour exprimer et communiquer les résultats aux utilisateurs de matériaux en vrac.
Le présent document s'applique aux matériaux en vrac granulaires, en poudre ou sous forme de pastilles. Un volume étalon est utilisé.
Le présent document ne s'applique pas à la détermination de l'empoussièrement dû à la réduction mécanique (par exemple, découpe, concassage) de matériaux solides en vrac.
Izpostavljenost na delovnem mestu - Meritve prašnosti razsutih materialov - 2. del: Metoda z vrtečim bobnom
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
oSIST prEN 15051-2:2024
01-julij-2024
Izpostavljenost na delovnem mestu - Meritve prašnosti razsutih materialov - 2. del:
Metoda z vrtečim bobnom
Workplace exposure - Measurement of the dustiness of bulk materials - Part 2: Rotating
drum method
Exposition am Arbeitsplatz - Messung des Staubungsverhaltens von Schüttgütern - Teil
2: Verfahren mit rotierender Trommel
Exposition sur les lieux de travail - Mesurage du pouvoir de resuspension des matériaux
pulvérulents en vrac - Partie 2 : Méthode du tambour rotatif
Ta slovenski standard je istoveten z: prEN 15051-2
ICS:
13.040.30 Kakovost zraka na delovnem Workplace atmospheres
mestu
oSIST prEN 15051-2:2024 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
oSIST prEN 15051-2:2024
oSIST prEN 15051-2:2024
DRAFT
EUROPEAN STANDARD
prEN 15051-2
NORME EUROPÉENNE
EUROPÄISCHE NORM
July 2024
ICS 13.040.30 Will supersede EN 15051-2:2013+A1:2016
English Version
Workplace exposure - Measurement of the dustiness of
bulk materials - Part 2: Rotating drum method
Exposition sur les lieux de travail - Mesurage du Exposition am Arbeitsplatz - Messung des
pouvoir de resuspension des matériaux pulvérulents Staubungsverhaltens von Schüttgütern - Teil 2:
en vrac - Partie 2 : Méthode du tambour rotatif Verfahren mit rotierender Trommel
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 137.
If this draft becomes a European Standard, 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.
This draft European Standard was established by CEN 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, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.
Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2024 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 15051-2:2024 E
worldwide for CEN national Members.
oSIST prEN 15051-2:2024
prEN 15051-2:2024 (E)
Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Requirements . 6
4.1 General . 6
4.2 Conditioning of the bulk material . 6
4.2.1 As-received condition . 6
4.2.2 Conditioning specifications . 6
4.3 Sample and environmental control . 6
4.4 Moisture content . 7
4.5 Bulk density . 7
4.6 Test procedure . 7
4.7 Replicate tests . 7
4.8 In-house / test powder . 7
5 Rotating drum method . 7
5.1 Description of test apparatus . 7
5.2 Particle size-selective foams . 10
5.3 Filters . 10
5.4 Ancillary equipment . 10
5.5 Preparation of test sample . 11
5.6 Preparation of test apparatus . 11
5.7 Running the test apparatus . 11
5.8 Weighing the foams and filters . 12
5.9 Determination of the inhalable, thoracic and respirable dustiness mass fractions. 13
5.10 Limit of detection (LOD) and limit of quantification (LOQ) . 13
6 Evaluation of dustiness . 14
7 Test report . 15
Annex A (normative) Flow rate and leak checks of the rotating drum . 16
Annex B (informative) Quality control of metal foams . 17
Annex C (informative) Test to identify outliers amongst values obtained from repeat tests . 19
Annex D (informative) LOD and LOQ procedure for gravimetric filters and foams . 21
Bibliography. 25
oSIST prEN 15051-2:2024
prEN 15051-2:2024 (E)
European foreword
This document (prEN 15051-2:2024) has been prepared by Technical Committee CEN/TC 137
“Assessment of workplace exposure to chemical and biological agents”, the secretariat of which is held
by DIN.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 15051-2:2013+A1:2016.
prEN 15051-2:2024 includes the following significant technical changes with respect to
EN 15051-2:2013+A1:2016:
— The introduction was revised to better explain the purpose of dustiness testing;
— Subclause 4.2.2: Inclusion of Conditioning specifications for standard testing and inter-comparison
in addition to as received testing;
— Subclause 4.3: Change in the tolerance of relative humidity (RH): Previously, RH was specified at
50 ± 10 % RH; now, it is specified at 50 ± 5 %;
— Subclause 4.8: Introduction of an in-house or test powder of relatively high dustiness for quality
purpose and to ensure reproducibility in testing;
— Subclause 5.7: Change in the minimum of repeat tests to be carried out from three to five and specify
procedure for reporting results based on the relative standard deviation.
— Subclause 5.10: Limit of detection (LOD) and limit of quantification (LOQ) has been added for the
determination and reporting of LOD and LOQ of the weighing of the filters, and the 80ppi and 20 ppi
foams;
— Clause 6: In Table 1, the respirable dustiness mass fraction (wR,A) upper limit for the very low
dustiness category has been changed from < 10 mg/m3 to < 20 mg/kg. As a result, the low category
has been revised from 10 to 60 mg/m3 to 20-60 mg/m3;
— Annex A: Flow rate and leak check, which is normative, has been added. It provides a procedure to
check, evaluate and report the flow rate and potential leaks through the rotating drum;
— Annex B (informative) for the quality control of metal foams has been added;
— Annex C (informative) provides a test to identify outliers amongst values obtained from repeat tests;
— Annex D (informative) provides an example of a procedure to evaluate the LOD and LOQ for
gravimetric filters and foams.
EN 15051 Workplace exposure — Measurement of the dustiness of bulk materials consists of the following
parts:
— Part 1: Requirements and choice of test methods;
— Part 2: Rotating drum method;
— Part 3: Continuous drop method.
oSIST prEN 15051-2:2024
prEN 15051-2:2024 (E)
Introduction
This document gives details of the design and operation of the rotating drum test method that categorizes
the dustiness of solid bulk materials, in terms of health-related mass fractions.
The dustiness values of a specific method can be used for comparing and ranking powders and are useful
for the purpose of safety by design and risk assessment. A dustiness categorization is presented to
provide users (e.g. manufacturers, producers, occupational hygienists and workers) with information on
the potential for dust emissions when the bulk material is handled or processed in workplaces. It provides
the manufacturers of bulk materials with information that can help to improve their products. It allows
the users of the bulk materials to assess the effects of pre-treatments, and also to select less dusty
products, if available. It is envisaged that different branches of industry might develop their own
categorization schemes using experimentally determined dustiness values of the bulk materials of
interest.
However, dustiness test methods measure dust at source emission and do not consider the transportation
of the airborne particles within a workplace environment to the breathing zone of a worker.
Concentrations of respirable or inhalable dust in the workplace air, resulting from the processing and
handling of bulk materials, will depend on a wide variety of factors (e.g. environmental factors, quantity
used, engineering controls, transport of particles from source to worker’s breathing zone, type of
activities). Therefore, dustiness values do not provide workplace exposure concentrations.
Although this document does not discuss in detail the analysis of dust released from bulk materials
(except in terms of gravimetric analysis), the test method produces samples with the potential for
chemical analysis of the contents. However, it is important to understand that for a mixture, the mass
percentage of a substance in the bulk material will be different (lower or higher) to the mass percentage
of the same substance in the dust collected by the foams and the filter using the rotating drum.
This document was originally developed based on the results of the European project SMT4-CT96-2074
Development of a Method for Dustiness Testing (see [1]). This project investigated the dustiness of 12
bulk materials, with the intention to test as wide a range of bulk materials as possible, i.e. magnitude of
dustiness, industrial sectors, chemical composition and particle size distribution. The first revision
considered important comments from industrial users of the standard (e.g. Industrial Minerals
Association), a number of research papers (for example, [2] and [3]) and the potential influence of the
expanding database of dustiness results. In this revised version, the performance and characteristics of
the metal foams for the sampling of the respirable fraction and important comments from industrial users
of the standard have been taken into account.
For the measurement of dustiness of bulk materials that possibly contain or release nano-objects and
their agglomerates and aggregates (NOAA) using the rotating drum, the reader should consult the
EN 17199 series [6, 7].
oSIST prEN 15051-2:2024
prEN 15051-2:2024 (E)
1 Scope
This document specifies the rotating drum test apparatus and associated test method for the
reproducible production of dust from a bulk material under standard conditions, and the measurement
of the inhalable, thoracic and respirable dustiness mass fractions, with reference to existing European
Standards, where relevant (see Clause 6).
This method is suitable for general bulk material handling processes, including all those processes where
the bulk material is dropped, or can be dropped. It differs from the continuous drop method presented in
EN 15051-3 [4]. In EN 15051-2, the same bulk material is repeatedly dropped, whilst in EN 15051-3, the
bulk material is dropped only once, but continuously.
Furthermore, this document specifies the environmental conditions, the sample handling and analytical
procedures, and the method of calculating and presenting the results. A categorization scheme for
dustiness is specified, to provide a standardized way to express and communicate the results to users of
the bulk materials.
This document is applicable to powdered, granular or pelletized bulk materials. A standard sample
volume is used.
This document is not applicable to test the dust released when solid bulk materials are mechanically
reduced (e.g. cut, crushed).
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 1540, Workplace exposure — Terminology
prEN 15051-1:2024, Workplace exposure — Measurement of the dustiness of bulk materials — Part 1:
Requirements and choice of test methods
ISO 15767, Workplace atmospheres — Controlling and characterizing uncertainty in weighing collected
aerosols
3 Terms and definitions
For the purpose of this document, the terms and definitions given in EN 1540 and prEN 15051-1 apply.
NOTE In particular, the following terms of EN 1540 are used in this document: airborne dust, collected sample,
dustiness, dustiness mass fraction, inhalable fraction, limit of detection, limit of quantification, respirable fraction,
thoracic fraction and health related fractions.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp/
— IEC Electropedia: available at https://www.electropedia.org/
3.1
pore rate number of a foam
grade number of a foam
range or number of pores per linear inch in a foam
Note 1 to entry: For example: grade 1723 indicates 17 to 23 pores/inch (ppi).
oSIST prEN 15051-2:2024
prEN 15051-2:2024 (E)
3.2
relative density of a foam
mass ratio between the porous metal foam and the mass of the same volume of the basic solid material
3.3
limit of detection
LOD
three times the estimated standard deviation of the mass of blank filters, accounting for the double
weighing, field blanks, filter handling and conditioning procedures
Note 1 to entry: The value of LOD, as defined here, does not take into account sources of variability beyond
weighing.
3.4
limit of quantification
LOQ
ten times the estimated standard deviation of the mass of blank filters
Note 1 to entry: The value of LOQ can be used as a threshold value to ensure accurate measurement of a substance.
4 Requirements
4.1 General
The test procedures described in prEN 15051-1:2024, Clause 5 shall be applied.
4.2 Conditioning of the bulk material
4.2.1 As-received condition
For the characterization of the bulk material under workplace conditions, the bulk material shall be sent
to the organization performing the dustiness test as placed on the market or as used by the downstream
user, in air-tight containers. It shall be tested in the state in which it was received.
4.2.2 Conditioning specifications
For standard testing and inter-comparison, test materials shall be conditioned at a relative humidity (RH)
of (50 ± 5) % before testing until they reach a stable weight. The conditioning time depends on the
amount of bulk material to be conditioned and shall be at least 48 h if the weight equilibrium is unknown.
Where a large amount of bulk material is required by the test method, the bulk shall be divided in smaller
quantities during conditioning in order to increase the exposed surface area of the material to the
conditioned air (see ISO 14488 [5]).
Additional conditioning of filters and metal foams may be required after assembly if the conditions during
transfer and assembly were significantly different from the ranges stated above.
4.3 Sample and environmental control
Bulk materials that have a large specific surface area are sensitive to environmental conditions such as
relative humidity, temperature and electrostatic effects, and to their own moisture content, compaction
and agglomeration. Therefore, for accurate results the test atmosphere shall be within a narrow range of
temperature and humidity. In all cases the environmental conditions shall be documented.
oSIST prEN 15051-2:2024
prEN 15051-2:2024 (E)
The following test conditions shall apply:
— relative humidity (RH): (50 ± 5) %;
— temperature: (21 ± 3) °C.
The test apparatus shall be electrically grounded.
NOTE In many cases, a separate determination of the particle size can be valuable.
4.4 Moisture content
The moisture content of the bulk material shall be determined and documented according to the
procedure given in prEN 15051-1:2024, 5.5 and Annex A.
4.5 Bulk density
The bulk density of the test material shall be determined and documented according to the procedure
given in prEN 15051-1:2024, Annex B.
4.6 Test procedure
The dustiness shall be tested according to the rotating drum test method described in Clause 5.
4.7 Replicate tests
Replicate tests shall be carried out according to 5.7.
4.8 In-house / test powder
For quality purpose and to ensure reproducibility in testing, a bulk material of relatively high dustiness
shall be purchased and analysed on regular basis according to the test method described in Clause 5.
Sufficient amount of material shall be bought and stored appropriately in air-tight containers to become ®
an in-house reference powder. Ballotini glass beads, such as Spheriglass 5000 CP00 , are an example
of suitable powder of relatively high dustiness, which could be acquired for this purpose (see
prEN 15051-1:2024, Annex C).
5 Rotating drum method
5.1 Description of test apparatus
The test apparatus required to determine the dustiness of bulk materials is shown in Figure 1, Figure 2
and Figure 3. ®
Spheriglass 5000 (CP00) is an example of a suitable product available commercially. This information is given for the convenience of users
of this document and does not constitute an endorsement by CEN of this product.
oSIST prEN 15051-2:2024
prEN 15051-2:2024 (E)
Key
1 air flow
2 inlet stage (protective filter)
3 dust generation section – rotating drum
4 longitudinal vanes (eight in total)
5 outlet stage / dust sampling system (two particle size selective foam stages and a back-up filter)
6 rotary coupler
7 rollers
8 in line mass-flow meter
9 control valve
10 vacuum pump
11 timer (time control circuit)
12 drive motor
Figure 1 — Outline of the rotating drum test apparatus
oSIST prEN 15051-2:2024
prEN 15051-2:2024 (E)
Figure 2 — Dimensions of the rotation drum
Key
1 20 ppi foam(s) (80 mm diameter)
2 80 ppi foam (80 mm diameter)
3 filter (80 mm diameter)
4 stainless steel grid / filter support
5 PTFE spacer rings
Figure 3 — Outlet stage / dust sampling system (two particle size selective foam stages and a
back-up filter)
oSIST prEN 15051-2:2024
prEN 15051-2:2024 (E)
−1
The test apparatus comprises a 300 mm diameter stainless steel drum rotating at 4 min , equipped with
eight longitudinal vanes to lift and let fall a known volume of the bulk material under test (the dust
generation section (3)), and a three-stage dust sampling system (the outlet stage (4)) through which the
−1
emitted dust cloud is drawn by a vacuum pump (8) at a flow rate of 38 l min for the duration of the test.
The stainless steel vanes of 230 mm length and 25 mm height are fixed longitudinally to the internal walls
of the drum and point radially inwards towards the centre of the drum. The test apparatus shall be
earthed.
The dust sampling system (4) comprises two particle size-selective foam stages in series followed by a
back-up filter (see Figure 2). Polytetrafluorethylene (PTFE) spacer rings of size 60 mm inner diameter
and 2 mm thickness are used to separate the two foam stages and the back-up filter to prevent cross
contamination. The entrance inner diameter of the three-stage dust sampling outlet shall be 60 mm and
an additional A PTFE spacer ring of size 60 mm inner diameter (2 mm thickness) can be placed at the
entrance of the three-stage dust sampling outlet (see Figure 2). Dust entering the conical passage and
into the sampling system gives an estimate of the inhalable fraction. The size selectors, in the form of
cylindrical plugs of 800 pores per metre (20 pores per inch) and 3 200 pores per metre (80 pores per
inch) porous metal foam, are chosen to select the thoracic and the respirable fractions, respectively. The
foams and the back-up filter are weighed before and after the test to provide the dustiness estimates of
the three size fractions. A glass fibre protective filter with a diameter of 150 mm is on the inlet of the
drum (2) to prevent dust contamination and to spread the air flow into the drum.
It is important to minimize leaks in the system. Additional seals can be fitted to the newly purchased
rotating drum inlet and outlet stage to minimize leaks.
The drum shall be made in stainless steel with the interior of the drum polished to provide a uniform
smooth surface.
NOTE The quality of the polish of the inner drum surface or roughness can potentially influence the dustiness
values.
The air flow rate through the test apparatus is monitored using an in-line mass flowmeter (6), and this
also provides an estimation of the volume of air sampled. The flow rate through the rotating drum test
should be checked at the inlet using a calibrated flowmeter and adjusted to 38 l/min if required (see
Annex A). A timing control circuit (9) automatically controls the operation of the test apparatus.
5.2 Particle size-selective foams
Porous metal foam size selectors with a reticulated open-cell structure are used to select the thoracic and
respirable dust fractions. Both size selectors have a diameter of 80 mm, the 800 pores per metre
(20 pores per inch) foam has two layers of 10 mm thickness or one single layer of 20 mm thickness, and
the 3 200 pores per metre (80 pores per inch) foam is a single layer of 12 mm thickness. PTFE tape is
stretched around the edge of each foam to form a seal and prevent the potential loss of dust through the
edge during testing. A minimum of two layers of PTFE tape is recommended.
When new foams are purchased, follow the procedure as specified in Annex B.
5.3 Filters
Filters with a diameter of 80 mm shall be used to collect the respirable particles that penetrate the foams.
The filter shall have a collection efficiency of at least 99 %. Choice of filter material depends on
subsequent analysis.
5.4 Ancillary equipment
The balance room or chamber, where weighing is carried out, shall have a temperature and humidity
maintained at a stable level, so that an acceptable weighing uncertainty is obtained, see ISO 15767.
oSIST prEN 15051-2:2024
prEN 15051-2:2024 (E)
An analytical balance capable of weighing 250 g to a resolution of 0,1 g shall be available for weighing the
samples of bulk material.
An analytical balance capable of weighing 150 g to a resolution of 0,01 mg shall be used for accurate
determination of the foams and filters. The weighing chamber of the analytical balance shall be large
enough to hold an 80 mm filter without it touching the walls. A weighing frame to position the foams and
filters on the balance pan may be used.
5.5 Preparation of test sample
Test samples shall be extracted from the bulk material using a method which will result in representative
sampling (see prEN 15051-1:2024, 5.3). A minimum of six samples is prepared. Sample bottles able to be
sealed shall be used to minimize contamination of the atmosphere.
Test samples with a volume of about 35 cm shall be extracted and weighed to the nearest 0,1 g.
5.6 Preparation of test apparatus
Prior to the tests being carried out, the rotating drum is cleaned thoroughly using a suitable vacuum
cleaner, wiped with a damp cloth and allowed
...
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