1、Designation: D4532 10Standard Test Method forRespirable Dust in Workplace Atmospheres Using CycloneSamplers1This standard is issued under the fixed designation D4532; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、 revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method provides details for the determinationof respirable dust concentration defined in terms of interna-tional
3、 convention in a range from 0.5 to 10 mg/m3inworkplace atmospheres. Specifics are given for sampling andanalysis using any one of a number of commercially availablecyclone samplers.1.2 The limitations on the test method are a minimumweight of 0.1 mg of dust on the filter, and a maximum loadingof 0.3
4、 mg/m2on the filter. The test method may be used athigher loadings if the flow rate can be maintained constant.1.3 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.4 This test method contains notes that are explanatory andare n
5、ot part of the mandatory requirements of the method.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to consult andestablish appropriate safety and health practices and deter-mine the applic
6、ability of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1356 Terminology Relating to Sampling and Analysis ofAtmospheresD3195 Practice for Rotameter CalibrationD5337 Practice for Flow Rate Calibration of PersonalSampling PumpsD6062 Guide for Personal Samplers of He
7、alth-RelatedAerosol FractionsD6552 Practice for Controlling and Characterizing Errors inWeighing Collected AerosolsD7440 Practice for Characterizing Uncertainty in Air Qual-ity MeasurementsE1 Specification for ASTM Liquid-in-Glass ThermometersE2251 Specification for Liquid-in-Glass ASTM Thermom-eter
8、s with Low-Hazard Precision Liquids2.2 Other International Standards:3ISO GUM Guide to the Expression of Uncertainty in Mea-surement, ISO Guide 98ISO 7708 Air QualityParticle Size Fraction Definitionsfor Health-Related SamplingISO 15767 Workplace AtmospheresControlling andCharacterizing Errors in We
9、ighing Collected AerosolEN 481 Workplace AtmospheresSize Fraction Defini-tions for the Measurement of Airborne Particles in theWorkplaceEN 13205 Workplace AtmospheresAssessment of Perfor-mance of Instruments for Measurement of Airborne Par-ticle Concentrations3. Terminology3.1 Definitions of Terms S
10、pecific to This Standard: Defini-tions of Terms Specific to This Standard (otherwise, consultD1356):3.1.1 respirable dust fractionfraction of airborne material(see Fig. 1) that would be collected by an idealized samplerfollowing the internationally-harmonized sampling conven-tions of ISO 7708, EN 48
11、1, Guide D6062, and Ref. (1).4NOTE 1The definition of the respirable dust fraction is a compromisebetween previous definitions, available samplers, and the fraction of dustthat penetrates to (rather than deposits in) the alveolar region of the lung.Local legal definitions may differ from the definit
12、ion adopted in this testmethod.3.2 For the terms and definitions related to characterizinguncertainty, see ISO GUM and Practice D7440.1This test method is under the jurisdiction of ASTM Committee D22 on AirQuality and is the direct responsibility of Subcommittee D22.04 on Workplace AirQuality.Curren
13、t edition approved April 1, 2010. Published June 2010. Originallyapproved in 1985. Last previous edition approved in 2003 as D4532 97(2003).DOI: 10.1520/D4532-10.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book
14、of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.4The boldface numbers in parentheses refer to the list of references at
15、the end ofthis test method.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4. Summary of Test Method4.1 Air is drawn through a cyclone or equivalent samplerfollowed by a tared filter, which is then re-weighed to deter-mine the mass o
16、f respirable dust. The air flow rate and time ofsampling provide the volume from which the dust mass wassampled. A time-weighted average respirable dust concentra-tion is calculated by dividing the mass by the total air volume.NOTE 2Samplers alternative to a cyclone (for example, foam-based orperson
17、al cascade impactors) may be used if they have desirable properties(for example, ease of use or uncertainty control) for intended application.Nevertheless, this test method is limited to cyclone samplers.5. Significance and Use5.1 This test method covers the determination of respirabledust concentra
18、tion in workplace atmospheres.5.2 Variations of the test method are in world-wide use fordetermining compliance relative to occupational exposurelevels.5.3 The test method may be used to verify dust controlmeasures.5.4 The test method may also be applied in research intohealth effects of dust in an
19、occupational setting.6. Apparatus6.1 Sampling UnitThe sampling unit consists of a pumpand a sampling head. The sampling head consists of a cycloneand a filter assembly.6.1.1 Evaluated Respirable Dust CycloneFor a list ofcommercially-available samplers and characteristics, see Re-search Report RR:D22
20、-1033.NOTE 3Bias relative to the international respirable dust criterion andthe dust size distribution being sampled (2-10) must be controlledsufficiently (see 13.2.4) for the application of intended use.6.1.2 Filter Cassette AssemblyFilter, filter-support pad,and filter cassette holder with suitabl
21、e caps. The filter shall benon-hygroscopic and a collection efficiency greater than 95 %for the dust of interest.NOTE 4As an example, most glass fiber and membrane filters withnominal pore size of 5 m will fulfill this requirement (11). PVC isrecommended for gravimetric analysis. The equilibrated fi
22、lter is pre-weighed by the user.NOTE 5It is preferable to use a conductive cassette because electro-static charge on the dust and a non-conductive cassette can result in asignificant bias (12-16). For controlling dust which may become attractedto the interior cassette walls, several filter holders e
23、quipped with ashielded respirable dust filter and cassette are commercially available,which may be weighed together with the filter.6.1.3 Personal Sampling PumpWith a flow rate uncer-tainty (see 13.2.1) less than 5 %. The pump pulsation ampli-tude may not exceed 620 % of the mean flow. The samplingp
24、ump is calibrated using Practice D5337.NOTE 6Cyclone samples collected with pulsating flow have beenshown to yield a negative bias as large as 22 % compared to samplescollected under steady flow (17).6.2 ChargerPump batteries shall be completely chargedwith an appropriate charger following the manuf
25、acturersinstructions or disposable batteries may be used.6.3 Weighing RoomWith temperature (20 6 2C) andhumidity (50 6 5 % Relative Humidity (RH) control to allowweighing with an analytical balance to accuracy required. SeeISO 15767 and Practice D6552 for controlling and character-izing errors in we
26、ighing collected aerosols.NOTE 7If a weighing room is not available, a filter equilibrationchamber can be used to equilibrate the filters in a temperature (20 6 2C)and humidity (50 6 5 % RH) controlled chamber.6.4 Analytical BalanceCapable of weighing to 0.01 mg orbetter, depending on application. P
27、articular care must be givento the proper zeroing of the balance.6.5 Charge NeutralizerTo eliminate static charge in thebalance case and on the filters during weighing. Po-210neutralizers if used must be replaced within nine months oftheir production date.6.6 Plane-Parallel PressCapable of giving a
28、force of atleast 1000 N (may be required if plastic filter holders are usedthat must be pressed together after insertion of the filter).6.7 Flow MeterWith precision equal to 2 % or betterwithin the range of the flow rate used. Calibrate the meter usingPractice D3195.6.8 ThermometerCapable of coverin
29、g the temperaturerange of interest with divisions every 0.1C (see SpecificationsE1 and E2251).NOTE 8It is encouraged to use a non-mercury thermometer tominimize environmental hazards.6.9 Flexible Tube with Two ClipsOne near the samplinghead, if the sampling head does not have a clip, and the othermi
30、dway between the sampling head and the pump. The lengthof the tube is dependent on how the sampling unit is worn. Alength of 0.7 to 0.9 m is suitable if the pump is attached to theworkers belt.6.10 ForcepsPreferably nylon.6.11 Rod or filter lifter.6.12 Petri DishesWith diameter slightly greater than
31、 thefilter.7. Preparation of Samplers Prior to Sampling7.1 Inspect the interior of the cyclone and clean it to keepaway from reentrainment of large particles. If the insideFIG. 1 Collection Efficiency of an Ideal Sampler Following theInternational Sampling ConventionsD4532 102surfaces are visibly sc
32、ored, replace the cyclone since the dustseparation characteristics of the sampler might be altered.7.2 Equilibrate all the filters in an environmentally con-trolled weighing room or equilibration chamber for at least twohours.7.3 Weigh the filters in the weighing room.7.3.1 Internally calibrate the
33、balance (zero balance) beforeuse.7.3.2 Grasp the filter with forceps and pass the filter severaltimes through a charge neutralizer to eliminate static charge, ifnecessary.7.3.3 Record the weight of filters.7.4 Place the tared filter and filter support in the filtercassette holder, close firmly, and
34、tape the circumference of thefilter holder. If necessary, use the press described in 6.6.7.5 Place caps to the filter holder and suitably cover theassembly to avoid contamination if it is held for any time priorto use.8. Sampling8.1 Remove the filter holder caps and connect the filterholder to the c
35、yclone as required by the manufacturer. Connectthe outlet of the sampling head to the calibrated pumps inletwith a piece of flexible tubing. Make sure all connections arefree of leaks by closing off the filter inlet.8.2 Attach the sampling head to the worker so that it islocated in the breathing zon
36、e. The workers breathing zoneconsists of a hemisphere 30-cm radius extending in front of theface, and measured from a line bisecting the ears. The samplinghead shall be placed in such a manner to prevent dust fromfalling into it and to avoid restricting the inlet. The pump canbe attached to the work
37、ers belt.8.3 Initiate sampling by turning the pump on and record theflow rate and the time. For long-term sampling, periodicallycheck the pump whether the pump functions properly. If anoticeable change of the flow rate is visually observed due tobending or blockage of tubing, turn off the pump and r
38、eset theflow rate. If unable to reset the flow rate to the original setting,terminate sampling and note the reason for termination.NOTE 9Depending on sample load, consecutive samples over the shiftmay be required. However, the sampling time should not exceed theoperating life of the batteries or the
39、 prevailing “full shift.” The nominalsampling period is eight hours. Sampling times shorter than a full shift arepermitted if the following occurs:The pressure drop across the filter exceeds the pumps capabilities; thatis, the filter becomes clogged.Specific working operations of shorter duration ar
40、e to be investigated.Determinations of variations of the exposure during a shift are made.8.4 At the end of the sampling period, turn the pump off andrecord the final flow rate and time.8.5 Remove the sampling unit from the worker and care-fully take the sampling equipment to a clean, dust-free area
41、.8.6 Measure the pump flow rate using the calibrated flowmeter. If the flow rates before and after sampling differ by morethan 5 %, consider the sample to be invalid.8.7 Remove the filter holder from the sampling head andreplace the filter holder caps.8.8 For each set of ten or fewer samples, submit
42、 a fieldblank sample. The filters and filter holders to be used as blanksare prepared and transported in the same manner as the samplesexcept that no air is drawn through them. Label these as blanks.8.9 The filter assembly should be returned to the laboratoryin a suitable container designed to preve
43、nt sample damage intransit.NOTE 10The sampler must not be inverted at any time or elsere-deposition of particles from the cyclone body onto the filter may occur.NOTE 11The preferred procedure is to personally transport samplesback to the laboratory such as by car or carry-on aircraft baggage. Ifcoll
44、ected samples need to be shipped by a shipping service, place samplepackages inside larger boxes and cushion with packing materials.9. Calibration and Standardization9.1 Air flow calibration of the sampling unit should becompleted before and after each sampling session. Mainte-nance and repairs, acc
45、ording to the manufacturers instructions,should be performed on a regular schedule and records kept fordocumentation. See Practice D5337 for guidance on flow ratecalibration.NOTE 12Make sure that the pump is connected to an appropriatesampling train, in the order of pump, tubing, inlet of sample med
46、ia holder,and the cyclone connected to the sample media holder.NOTE 13Some samplers are accompanied with their own calibrationchamber and thus, do not need a jar to calibrate the pump; refer to themanufacturers manual. Alternatively, a calibrated flow meter (see 6.7)may be used to check the field fl
47、ow rate at the beginning and end ofsampling.NOTE 14It is critical that the flow rate required for the sampler be setat the time and location of sampling. If the temperature and pressure in thesampling environment differ from where the pump flow rate was set, thevolumetric flow rate needs to be readj
48、usted prior to sampling.10. Procedure10.1 Carefully swab the outer surface of the filter assemblywith a lintless paper towel moistened with water beforeopening the filter holder to minimize sample contamination.10.2 Remove the caps of the filter holder and equilibrate inan environmentally controlled
49、 room or equilibration chamberfor at least two hours.10.3 Open the filter holder and carefully remove the filterwith forceps from the holder with the aid of a rod or filter lifterinserted into the outlet hole of the filter holder. Handle thefilters very gently by the edge to avoid loss of dust. Transfer thefilter to a petri dish. Place the filter in the weighing room.10.4 Weigh the filter preferably on the same analyticalbalance that was used to determine the tare weight. If theoriginal balance is not available or is inoperative, then a
