CEN/TR 16013-3:2012

Workplace exposure - Guide for the use of direct-reading instruments for aerosol monitoring - Part 3: Evaluation of airborne particle concentrations using photometers

This Technical Report describes the use of photometers for the determination of airborne particles belonging to the respirable fraction and gives details on their limitations and possible uses in the field of occupational hygiene.
NOTE   Photometers can also be used to detect other size fractions of airborne particles after aerodynamic pre-separation, but these are not the focus of this Technical Report.
The method complements existing conventional long-term aerosol particle sampling and can be used for:
-   instantaneous (direct-reading) measurement,
-   time-related monitoring,
-   investigation of space-related aerosol evolution (mapping), and
-   exposure visualization.
The method enables e.g.:
-   detection and relative quantification of concentration peaks due to specific operations (bagging, sanding, etc.);
-   identification of most exposed workers with a view to more detailed studies of risks and prevention measures to be applied; and
-   detection of dust emission sources and their relative magnitudes.

Exposition am Arbeitsplatz - Leitfaden für die Anwendung direkt anzeigender Geräte zur Überwachung von Aerosolen - Teil 3: Bewertung der Konzentration luftgetragener Partikel mit Photometern

Exposition au poste de travail - Guide d'utilisation des instruments à lecture directe pour la surveillance des aérosols - Partie 3 : Évaluation des concentrations de particules en suspension dans l'air à l'aide de photomètres

Le présent Rapport technique décrit l’utilisation de photomètres pour la détermination des particules en suspension dans l’air appartenant à la fraction alvéolaire et en précise les limites et les utilisations possibles dans le cadre de l’hygiène du travail.
NOTE   Des photomètres peuvent également être utilisés pour détecter d’autres fractions de taille de particules en suspension dans l’air après une séparation aérodynamique préalable, mais ils ne font pas l’objet du présent Rapport technique.
Complémentaire de l’échantillonnage classique existant de longue durée des particules d’aérosol, cette méthode peut être utilisée pour :
-   un mesurage quasi instantané (lecture directe) ;
-   une surveillance dans le temps ;
-   un examen des variations spatiales des aérosols (cartographie) ; et
-   une visualisation de l’exposition.
A titre d’exemples, cette méthode permet :
-   la détection et la quantification relative des pics de concentration dus à des opérations spécifiques (ensachage, ponçage, etc.) ;
-   l’identification des travailleurs les plus exposés en vue d’études plus approfondies des risques et des mesures de prévention à appliquer ; et
-   la détection des sources d’émission de poussières et leurs importances relatives.

Izpostavljenost na delovnem mestu - Vodilo za uporabo instrumentov z neposrednim odčitavanjem za monitoring aerosolov - 3. del: Vrednotenje koncentracij lebdečih delcev s fotometri

To tehnično poročilo opisuje uporabo fotometrične metode za določitev delcev v zraku, ki pripadajo vdihani frakciji, in zagotavlja podrobnosti o njihovih omejitvah in možnih načinih uporabe na področju higiene dela.

General Information

• Status: Published
• Publication Date: 16-Oct-2012
• ICS: 13.040.30 - Workplace atmospheres
• Technical Committee: CEN/TC 137 - Assessment of workplace exposure
• Drafting Committee: CEN/TC 137/WG 3 - Particulate matter
• Current Stage: 9093 - Decision to confirm - Review Enquiry
• Completion Date: 12-Jun-2015
• Ref Project: SIST-TP CEN/TR 16013-3:2012 - Workplace exposure - Guide for the use of direct-reading instruments for aerosol monitoring - Part 3: Evaluation of airborne particle concentrations using photometers

Standards Content (Sample)

SLOVENSKI STANDARD
01-december-2012
,]SRVWDYOMHQRVWQDGHORYQHPPHVWX9RGLOR]DXSRUDERLQVWUXPHQWRY]
QHSRVUHGQLPRGþLWDYDQMHP]DPRQLWRULQJDHURVRORYGHO9UHGQRWHQMH
NRQFHQWUDFLMOHEGHþLKGHOFHYVIRWRPHWUL
Workplace exposure - Guide for the use of direct-reading instruments for aerosol
monitoring - Part 3: Evaluation of airborne particle concentrations using photometers
Exposition am Arbeitsplatz - Leitfaden für die Anwendung direkt anzeigender Geräte zur
Überwachung von Aerosolen - Teil 3: Ermittlung der Konzentrationen luftgetragener
Partikel mit Photometern
Exposition au poste de travail - Guide d'utilisation des instruments à lecture directe pour
la surveillance des aérosols - Partie 3 : Évaluation des concentrations de particules en
suspension dans l'air à l'aide de photomètres
Ta slovenski standard je istoveten z: CEN/TR 16013-3:2012
ICS:
13.040.30 Kakovost zraka na delovnem Workplace atmospheres
mestu
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

TECHNICAL REPORT
CEN/TR 16013-3
RAPPORT TECHNIQUE
TECHNISCHER BERICHT
October 2012
ICS 13.040.30
English Version
Workplace exposure - Guide for the use of direct-reading
instruments for aerosol monitoring - Part 3: Evaluation of
airborne particle concentrations using photometers
Exposition au poste de travail - Guide d'utilisation des Exposition am Arbeitsplatz - Leitfaden für die Anwendung
instruments à lecture directe pour la surveillance des direkt anzeigender Geräte zur Überwachung von Aerosolen
aérosols - Partie 3 : Évaluation des concentrations de - Teil 3: Bewertung der Konzentration luftgetragener
particules en suspension dans l'air à l'aide de photomètres Partikel mit Photometern

This Technical Report was approved by CEN on 10 June 2012. It has been drawn up by the Technical Committee CEN/TC 137.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, 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. CEN/TR 16013-3:2012: E
worldwide for CEN national Members.

Contents Page
Foreword . 3
Introduction . 4
1 Scope . 5
2 Operating Principle . 5
2.1 General . 5
2.2 Light scattering . 5
2.3 Instrument response — Effects of airborne particle properties . 6
3 Instrument types . 8
3.1 General . 8
3.2 Passive aerosol monitors . 9
3.3 Active aerosol monitors . 9
3.4 Size-selective aerosol monitors . 9
4 Calibration . 10
4.1 General . 10
4.2 Factory calibration . 10
4.3 Optical reference element . 11
4.4 Gravimetric reference . 11
5 Choice of aerosol monitor . 12
5.1 General . 12
5.2 Active or passive aerosol monitors . 12
5.3 Mass concentration range . 12
5.4 Hazardous work environments . 13
5.5 Size selection. 13
6 Procedure for making aerosol measurements using photometers . 13
6.1 Instrument operating procedure. 13
6.2 Sampling strategies . 14
7 Limitations of use and sources of error . 15
8 Cleaning and maintenance . 15
Annex A (informative) Influence of physical parameters of aerosol particles and their
polydispersity on photometer measurement . 17
A.1 General . 17
A.2 Bias maps . 17
Annex B (informative) Currently available photometers . 21
Bibliography . 24

Foreword
This document (CEN/TR 16013-3:2012) 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.
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.
CEN/TR 16013 consists of the following parts, under the general title Workplace exposure — Guide for the use
of direct-reading instruments for aerosol monitoring:
 Part 1: Choice of monitor for specific applications;
 Part 2: Evaluation of airborne particle concentrations using Optical Particle Counters;
 Part 3: Evaluation of airborne particle concentrations using photometers.
Introduction
All photometer-based direct-reading aerosol monitors use the principle of light scattering to determine airborne
particle concentration. Here, a light source (usually produced by a laser or diode) is collimated and illuminates
airborne particles entering a sensing volume. The instrument optics are usually designed such that the intensity
of the light scattered at a particular angle is proportional principally to the respirable fraction of the airborne
particle concentration. Other physical properties of the aerosol such as particle size, refractive index and
particle shape, will affect their response by varying degrees (see [7]) although this can be minimised by careful
design of the photometer. Therefore, photometer-based direct-reading aerosol monitors are not ideal for the
measurement of worker exposure or to check whether threshold limit values of industrial dust concentrations
are exceeded. Their main advantage is that they give an almost instantaneous measure of airborne particle
concentration, thereby reducing considerably the time and effort associated with standard gravimetric methods.
They are also better at measuring aerosols with high vapour pressures that would normally evaporate during
standard gravimetric analysis. Some instruments include a pre-classifier on the inlet (cyclone or impactor) to
make the overall response closer to the respirable dust definition.
Photometers are therefore best suited to assess variations of airborne particle concentration in time or space
and to check for any sudden change of concentration. Typical applications are:
 walk-through surveys;
 background sampling to assess concentration variations and mean concentration during a working
shift period;
 assessment of the effectiveness of dust control systems;
 measurement of indoor air quality;
 as part of exposure video visualization systems.
For measurement of personal exposure they should be considered as complementary to conventional filter-
based gravimetric methods (see [2]), although with careful calibration, they can also give an accurate measure
of respirable dust exposure, i.e. that which enters the mouth and nose and passes to the lower regions of the
respiratory system (see EN 481).
1 Scope
This Technical Report describes the use of photometers for the determination of airborne particles belonging to
the respirable fraction and gives details on their limitations and possible uses in the field of occupational
hygiene.
NOTE Photometers can also be used to detect other size fractions of airborne particles after aerodynamic pre-
separation, but these are not the focus of this Technical Report.
The method complements existing conventional long-term aerosol particle sampling and can be used for:
 instantaneous (direct-reading) measurement,
 time-related monitoring,
 investigation of space-related aerosol evolution (mapping), and
 exposure visualization.
The method enables e.g.:
 detection and relative quantification of concentration peaks due to specific operations (bagging,
sanding, etc.);
 identification of most exposed workers with a view to more detailed studies of risks and prevention
measures to be applied; and
 detection of dust emission sources and their relative magnitudes.
2 Operating Principle
2.1 General
A laser or light emitting diode is used to produce a high intensity source of light, which is usually in the visible
near-infrared spectrum. This is collimated and illuminates airborne particles entering the sensing volume of the
instrument. The optical sensing volume is created by intersection of illuminating and detecting light beams as
shown in Figure 1. The intensity of the light scattered at a particular angle is proportional to the airborne particle
concentration and is detected using sensitive photomultipliers or photodiodes with response spectra covering
approximately the source emission spectra.
2.2 Light scattering
Interaction of a light beam with an airborne particle in suspension can cause several effects: absorption of part
of the light, reflection, refraction or diffraction of the beam. These combined effects result in scattering of the
incident light in every direction. The illumination and collection optics are arranged inside a photometer so that
light scattered at a fixed range of angles reaches the detector (see Figure 1). Depending on the design, these
º º º
instruments can measure the scattered light in the region of θ = 90 , 45 or less than 30 . Choice of observation
angle plays a prominent part in detection. Front scattering is relatively insensitive to changing airborne particle
º
refractive index and so forward-scattering photometers with scattering angles < 30 are less sensitive to the
º
refractive index of the aerosol than instruments with a 90 scattering angle. However, at small scattering angles,
photometers overestimate particles smaller than 1,5 µm.
Key
1 light source
2 incident light
3 aerosol flow
4 lens
5 light detector
6 scattered light
7 scattering angle
8 light stop
9 sensing volume
10 lens
Figure 1 — Light scattering aerosol photometer
2.3 Instrument response — Effects of airborne particle properties
2.3.1 General
For spherical particles of known refractive index the instrument response can be calculated by applying Mie's
light scattering theory (see [13]). The calculated response for a typical light scattering photometer is shown in
Figure 2.
Key
X particle diameter, in micrometres (µm)
...