BS PD CEN TR 16013-1-2010 Workplace exposure — Guide nfor the use of direct-reading ninstruments for aerosol nmonitoring nPart 1 Choice of monitor for specific napplications《工作场所暴露.pdf

1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationPD CEN/TR 16013-1:2010Workplace exposure Guidefor the use of direct-readinginstruments for aerosolmonitoringPart 1: Choice of monitor for specificapplicationsPD CEN/TR 16013-1:20

2、10 PUBLISHED DOCUMENTNational forewordThis Published Document is the UK implementation of CEN/TR 16013-1:2010.The UK participation in its preparation was entrusted to TechnicalCommittee EH/2/2, Work place atmospheres.A list of organizations represented on this committee can beobtained on request to

3、its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. BSI 2010ISBN 978 0 580 69045 7ICS 13.040.30Compliance with a British Standard cannot confer immunity fromlegal obligations.This Published Document w

4、as published under the authority of theStandards Policy and Strategy Committee on 31 July 2010Amendments issued since publicationDate Text affectedPD CEN/TR 16013-1:2010TECHNICAL REPORT RAPPORT TECHNIQUE TECHNISCHER BERICHT CEN/TR 16013-1 May 2010 ICS 13.040.30 English Version Workplace exposure - G

5、uide for the use of direct-reading instruments for aerosol monitoring - Part 1: Choice of monitor for specific applications Exposition au poste de travail - Guide dutilisation des instruments lecture directe pour la surveillance des arosols - Partie 1: Choix du moniteur pour des applications spcifiq

6、ues Exposition am Arbeitsplatz - Leitfaden fr die Anwendung direkt anzeigender Gerte zur berwachung von Aerosolen - Teil 1: Auswahl des Monitors fr besondere Anwendungsflle This Technical Report was approved by CEN on 13 March 2010. It has been drawn up by the Technical Committee CEN/TC 137. CEN mem

7、bers 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

8、, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2010 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Mem

9、bers. Ref. No. CEN/TR 16013-1:2010: EPD CEN/TR 16013-1:2010CEN/TR 16013-1:2010 (E) 2 Contents Page Foreword 3Introduction .41 Scope 62 Abbreviations .63 Principles of direct-reading aerosol monitoring methods 63.1 General 63.2 Vibrational mass methods 73.2.1 Piezoelectric mass monitors 73.2.2 TEOM T

10、apered Element Oscillating Microbalance 93.3 Beta mass monitors . 123.3.1 Operating principle . 123.3.2 Determination of mass concentration of health-related fractions . 143.3.3 Calibration of beta mass monitors 143.3.4 Advantages and disadvantages 143.3.5 Currently available beta mass monitors 153.

11、4 Methods of optical measurement of aerosols . 163.4.1 General . 163.4.2 Photometers 163.4.3 Optical particle counters 204 Requirements for different applications of direct-reading dust monitors 234.1 General . 234.2 Walk through surveys 234.3 Identification of main process or source emitting aeroso

12、ls 234.4 Use with video visual techniques . 234.5 Assessing efficiency of control systems . 244.6 Watchdogs to monitor levels in workplaces and ensure controls are working . 244.7 Surrogate personal exposure assessment 24Bibliography . 25PD CEN/TR 16013-1:2010CEN/TR 16013-1:2010 (E) 3 Foreword This

13、document (CEN/TR 16013-1:2010) 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 pat

14、ent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. CEN/TR 16013, Workplace exposure Guide for the use of direct-reading instruments for aerosol monitoring, consists of the following parts: Part 1: Choice of monitor for specific applications Pa

15、rt 2: Evaluation of airborne particle concentrations using Optical Particle Counters Part 3: Evaluation of airborne particle concentrations using photometers (in preparation) PD CEN/TR 16013-1:2010CEN/TR 16013-1:2010 (E) 4 Introduction The assessment of aerosols in the workplace can have several aim

16、s, including: a) estimation of the mean concentration of health-related aerosol particles (see EN 481) during a working shift period (workplace characteristics or personal exposure by static or personal sampling); b) sampling to provide a sample of airborne particles for later analysis (gravimetric,

17、 morphological, chemical, physical, mineralogical, etc., see EN 482); c) evaluation of almost instantaneous concentrations produced by various work activities using automatic instruments (photometers, -attenuation instruments, vibrational mass balance instruments); d) evaluation of almost instantane

18、ous concentrations and particle size distributions (optical particle counters OPC). This Technical Report concerns items c) and d), gives the principles, and details the general conditions to be satisfied. In occupational hygiene, no measurement procedure recommends exposure monitoring using direct-

19、reading aerosol monitors. These instruments should instead be considered as permitting a complementary approach to the conventional filter-based gravimetric method. The different types of information obtained are explained in Figure 1. a) b) Key X sample number (time) Y concentration (arb units) Fig

20、ure 1 Information from integrated filter sampling vs. continuous monitoring There is a wide range of portable and personal direct-reading aerosol monitors available. Recent advances in modern electronics and battery technology means direct-reading dust monitors are becoming smaller and lighter and o

21、f relatively low price. In addition to reliance on compliance with Occupational Exposure Limits, emphasis is now also being placed on control banding and advice on suitable control systems. This has led to new roles being identified for direct-reading aerosol monitors in ensuring that systems deploy

22、ed to control exposure to airborne dusts actually work. Some types of direct-reading aerosol monitors appear to be well suited to evaluate prevention action efficiency and to space- and time-related monitoring of concentration. PD CEN/TR 16013-1:2010CEN/TR 16013-1:2010 (E) 5 All instruments mentione

23、d in this document (see, in particular, Tables 2, 4, 6, 8 and 10) are examples of suitable products available commercially. This information is given for the convenience of users of this Technical Report only and does not constitute an endorsement by CEN of these products. PD CEN/TR 16013-1:2010CEN/

24、TR 16013-1:2010 (E) 6 1 Scope This Technical Report describes the principles underlying the evaluation of one or more aerosol fractions using direct-reading aerosol monitors. The currently available methods for monitoring levels of aerosols in workplaces for a range of different purposes are describ

25、ed and details are given of their limits and possibilities in the field of occupational hygiene. The document does not cover the sampling of aerosols for compliance with occupational exposure limits or the collection of aerosol particles for subsequent analysis. 2 Abbreviations For the purposes of t

26、his document, the following abbreviations apply. DRAM direct-reading aerosol monitor LOD limit of detection OEL occupational exposure limit OPC optical particle counter PM particulate matter TEOM tapered element oscillating microbalance TSP total suspended particulate 3 Principles of direct-reading

27、aerosol monitoring methods 3.1 General There are many methods, based on different physical principles, for the instantaneous measurement of aerosols. Instruments used are generally called direct-reading or continuous monitoring instruments. Depending on their design, they can give the instantaneous

28、or sequential concentration and can sometimes even measure particle size distribution. Instantaneous measurement has several advantages: a) immediate knowledge of the result without going through the laboratory, whence the possibility of rapid intervention (e.g. implementation of a ventilation syste

29、m); b) continuous measurement, long-distance surveillance, concentration record over time, mean concentration integration and calculation in selected periods, maxima and minima determination, source location, etc.; c) measurement of concentration for particles of unstable composition (e.g. volatile

30、substances); d) monitoring and control of aerosol concentration. Depending on the principles used, automatic methods can be classed into the following three main groups: vibrational mass method (see 3.2); beta attenuation method (see 3.3); optical methods (see 3.4). PD CEN/TR 16013-1:2010CEN/TR 1601

31、3-1:2010 (E) 7 3.2 Vibrational mass methods 3.2.1 Piezoelectric mass monitors 3.2.1.1 Operating principle Particles drawn into the instrument are collected on the surface of a piezoelectric crystal, forming part of a quartz crystal-based oscillating circuit (see Figure 2). Key 1 piezoelectric crysta

32、l 2 frequency Figure 2 Schematic of piezoelectric mass monitor The mass of deposited particles causes a reduction in the oscillation frequency f. The changed frequency is compared with the previous recorded initial frequency or a control circuit frequency. The frequency reduction is directly proport

33、ional to the particle mass (see 8). The proportionality factor kfexpresses the crystal sensitivity with respect to the deposited weight. It is constant for each crystal (see 7) and its value varies, in most cases, by approximately 200 Hz/g. If the frequency change during sampling, for a time t, is f

34、, the weight of collected dust will be fkfand the aerosol mean concentration can be calculated according to Equation (1): fsktQfC= (1) where C is the aerosol mean concentration, in milligrams per cubic metre;f is the change resonance frequency, in Hertz; Q is the sampling flow rate, in litres per mi

35、nute; ts is the sampling time, in minutes; kf is the crystal mass sensitivity, in Hertz per microgram The method is very sensitive and allows low concentrations of the order of several tens of micrograms per cubic metre to be measured. However, it is limited to fine particles (usually smaller than 1

36、0 m) because of the small mechanical force between the particle and the crystal surface: if its mass is high, the particle cannot follow the vibration frequency. This is also a problem for high loads when there is lack of coupling between the PD CEN/TR 16013-1:2010CEN/TR 16013-1:2010 (E) 8 outermost

37、 layers of particles and the crystal. This requires the crystal to be regularly cleaned and may limit the monitoring duration. 3.2.1.2 Determination of mass concentration of health-related fractions The change in frequency of crystal is directly proportional to the mass of particles deposited and is

38、 therefore largely independent of the physical and chemical properties of the particles. There is no need therefore to use on-site calibration factors, providing that the crystal is not overloaded. Because of particle size limitations on particle/sensor coupling (mentioned above) only the mass conce

39、ntration of the respirable fraction is measurable. Respirable size selection can be achieved using any suitable size selector; one instrument uses a single stage impactor with the respirable particles deposited on the crystal by electrostatic precipitation. Another instrument uses multiple crystals

40、as the collection substrate for size separated particles in a 10-stage cascade impactor. 3.2.1.3 Calibration of piezoelectric instruments Each crystal sensor has its own frequency response and so the instrument incorporating the crystal will be calibrated in the factory to give the required mass res

41、ponse. Provided that the crystal is not damaged, no further calibration is required. 3.2.1.4 Advantages/disadvantages of piezoelectric instruments Table 1 gives advantages and disadvantages of piezoelectric instruments. Table 1 Advantages/disadvantages of piezoelectric instruments Advantages Disadva

42、ntages direct measurement of dust mass usage limited by dust loading on crystal no on-site calibration required regular cleaning of crystal required response independent of chemical composition and particle size (below 10 m) only suitable for respirable particles relatively easy to use PD CEN/TR 160

43、13-1:2010CEN/TR 16013-1:2010 (E) 9 3.2.1.5 Currently available piezobalance instruments Table 2 gives an overview on currently available piezobalance instruments. Table 2 Currently available piezobalance instruments Name aPortable/ personal Size Weight Size selection Flow rate Response time Accuracy

44、 Measure-ment range mm kg l/min s mg/m3Kanomax Piezo-balance dust monitor Model 3511portable 311 170 130 2 respirable fraction by impactor 1 from 0 mg/m3 to 1 mg/m3: 24 s from 1 mg/m3 to 10 mg/m3: 120 s 10 % of reading 0,02 to 10 California Measure-ments Inc, PC-2HX QCMreal-time cascade impactor por

45、table, but mains- operated (battery- powered version by special order) cascade impactor: 35 12,5 32 control unit: 18 43 32 5,4 10 10 stages (0,1 m to 14 m) 2 for average concentration 0,05 mg/m3: 30 s not given 0,005 to 1 NOTE “Accuracy“ is defined by the manufacturers. aKanomax Piezo-balance dust m

46、onitor Model 3511and California Measurements Inc, PC-2HX QCMreal-time cascade impactor are examples of suitable products available commercially. This information is given for the convenience of users of this Technical Report and does not constitute an endorsement by CEN of these products. 3.2.2 TEOM

47、 Tapered Element Oscillating Microbalance 3.2.2.1 Operating principle This device is similar in principal to the piezoelectric microbalance but the oscillating frequency is applied to a tapered glass tube equipped with sampling filter at its narrow end (see Figure 3). PD CEN/TR 16013-1:2010CEN/TR 16

48、013-1:2010 (E) 10 Key 1 filter 2 tapered glass tube f frequency Figure 3 Schematic of the TEOM device The 13 mm diameter filter responsible for collecting the sampled aerosol particles is held inside a plastic cassette that is a close push-fit to the glass tube. The top part of the tapered tube is c

49、oated with an electrically conducting layer and it is placed between two flat electrodes, which maintain a continuous electric field. An oscillating current flows through the conducting layer, prompting vibration of the tapered tube. The vibration frequency is measured by an optical system comprising an LED photo-emitting diode and a phototransistor. The pulsating current linked to the tapered tube oscillations is amplified and ret