1、Designation: D 4532 97 (Reapproved 2003)Standard Test Method forRespirable Dust in Workplace Atmospheres1This standard is issued under the fixed designation D 4532; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last r
2、evision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method is useful for the determination ofrespirable dust (see Terminology D 1356) in a range from 0.5to 10 mg/m3i
3、n workplace atmospheres.1.2 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 applicability of regulatory limita
4、tions prior to use.2. Referenced Documents2.1 ASTM Standards:2D 1356 Terminology Relating to Sampling and Analysis ofAtmospheresD 3195 Practice for Rotameter CalibrationD 5337 Practice for Flow Rate Calibration of PersonalSampling PumpsD 6062M Guide for Personal Samplers of Health-RelatedAerosol Fra
5、ctions MetricE1 Specification for ASTM Liquid-in-Glass Thermometers3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 respirable fraction of the dustthat mass whichpasses through a cyclone at the stated conditions (1, 2).34. Summary of Test Method4.1 Air is accurately drawn for a
6、 measured period of timethrough a 10-mm cyclone followed by a tared filter. Therespirable dust concentration is calculated from the weight gainof the filter and the total volume of air sampled.5. Significance and Use5.1 This test method covers the determination of respirabledust in workplace atmosph
7、eres.5.2 The limitations on the test method are a minimumweight of 0.2 mg of dust on the filter, and a maximum loadingof 0.3 mg/cm2on the filter. The test method may be used athigher loadings if the flow rate can be maintained constant.6. Apparatus6.1 The sampling unit consists of a pump and a sampl
8、inghead. The sampling head consists of a 10-mm cyclone and afilter assembly.6.1.1 PumpA personal sampling pump with a flow rateaccurate to 65 %. Pump pulsation not to exceed 620 % of themean flow. The pump must be capable of maintaining the meanflow constant to within 65 % during the sampling period
9、.Calibrate the sampling pump using Practice D 5337.6.1.2 Sampling HeadThe sampling head consists of a10-mm cyclone, a filter, a filter-support pad, and a filter holderwith suitable caps (see Fig. 1).6.1.2.1 The cyclone4must be shown to be unbiased relativeto the appropriate respirable dust criterion
10、 and the dust sizedistribution being sampled (3, 4, 5, 6). Based on the cyclonepenetration curve for non-pulsating flow measured with amonodisperse aerosol, the bias in the test method is shown inFig. 2 for sampling rates appropriate for individual cyclones.(7).6.1.2.2 Cyclone samples collected with
11、 pulsating flow havebeen shown to yield a negative bias as large as 22 % comparedto samples collected under steady flow (8).6.1.2.3 Electrostatic charge on the dust and a non-conductive sampler can cause bias as large as 50 %. (9).6.1.3 The filter shall be non-hygroscopic and a collectionefficiency
12、greater than 95 % for the dust cloud of interest. Thefilter and its filter support shall be 37 mm in diameter.NOTE 1As an example, most glass fiber and membrane filters with1This test method is under the jurisdiction of ASTM Committee D22 on AirQuality and is the direct responsibility of Subcommitte
13、e D22.04 on WorkplaceAtmospheres.Current edition approved April 10, 2003. Published June 2003. Originallyapproved in 1985. Last previous edition approved in 1997 as D 4532 97.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For
14、 Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3The boldface numbers in parentheses refer to the list of references at the end ofthis test method.4The sole source of the 10-mm cyclones known to the committee at this time isDorr-Olive
15、r, Inc., Milford, CT 06460. If you are aware of alternative suppliers,please provide this information toASTM Headquarters. Your comments will receivecareful consideration at a meeting of the responsible technical committee,1whichyou may attend.1Copyright ASTM International, 100 Barr Harbor Drive, PO
16、 Box C700, West Conshohocken, PA 19428-2959, United States.nominal pore size of 5 m will nearly always fulfill this requirement (10).PVC is recommended for gravimetric analysis. The equilibrated filter ispreweighed by the user. The weight of the filter holder is not used in anydetermination of weigh
17、t gain in this test method. The filter holder materialmust not contribute to any weight change of the filter.6.1.4 ChargerPump batteries shall be completely chargedwith appropriate charger following the manufacturers instruc-tions or disposable batteries may be used.6.1.5 Suitable means is provided
18、for separately attaching thepump and the sampling head to the appropriate person.6.2 Buret, capacity of 1 L, used as a soap bubble meter forcalibration of the sampling unit.6.3 Barometer, capable of measuring atmospheric pressureto 60.1 kPa.6.4 Stopwatch, capable of measuring to 60.1 s.6.5 Weighing
19、Room, with temperature and humidity controlto allow weighing with an analytical balance to 60.01 mg.6.6 Analytical Balance, capable of weighing 60.01 mg orbetter. Particular care must be given to the proper zeroing ofthe balance. The same analytical balance and weights must beused for weighing filte
20、rs before and after sample collection.6.7 Charge Neutralizer, to eliminate static charge in thebalance case and on the filters during weighing. ReplacePo-210 neutralizers 9 months after production date.6.8 Plane-Parallel Press, capable of giving a force of atleast 1000 N (may be required if plastic
21、filter holders are usedthat must be pressed together after insertion of the filter).6.9 Tapered Tube Flow Meter, with precision 62% orbetter within the range of the flow rate used. Calibrate themeter using Practice D 3195.6.10 Thermometer, dry bulb, 0 to 50C with divisions every0.1C. (ASTM thermomet
22、ers number 90C and 91C.) (SeeSpecification E1.)6.11 Manometer, 0 to 250 mm of water (0 to 0.25 kPa) formeasuring the pressure drop across the sampling head.6.12 Flexible Tube with Two Clips, one near the samplinghead, if the sampling head does not have a clip, and the othermidway between the samplin
23、g 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.6.13 Jar, leakproof, of suitable size to contain the samplinghead during calibration of sampling system. (See and Fig. 3).57. Sampl
24、ing7.1 Clean and inspect the interior of the cyclone. If theinside surfaces are visibly scored, replace the cyclone since thedust separation characteristics might be altered.7.2 Condition all filters to a constant weight. Record thefilter weight.7.3 Place the tared filter and filter support in the f
25、ilter holder,close firmly, and tape the circumference of the filter holder. Ifnecessary, use the press described in 6.8. Suitably cover theassembly to avoid contamination if it is held for any time priorto use.7.4 Assemble sampling apparatus as shown in Fig. 1.7.5 Run the pump for 5 min to stabilize
26、 the flow rate.7.6 Remove the filter holder caps and connect the filterholder to the cyclone as required by the manufacturer. Connectthe outlet of the sampling head to the pumps inlet with a pieceof flexible tubing. Check to be sure all connections are free ofleaks by closing off the filter inlet. F
27、low should stop in 10 to 15s.7.7 Check the sampling unit for proper operation, check forleaks, and measure the flow rate.7.8 Sample at 1.7 L/min for the Dorr-Oliver 10-mm cy-clone, or as directed by manufacturer of specific cyclones.Depending on sample load, consecutive samples over the shiftmay be
28、required. However, the sampling time should notexceed the operating life of the batteries or the prevailing “fullshift.” The nominal sampling period is 8 h. Sampling timesshorter than a full shift are permitted if the following occurs:7.8.1 The pressure drop across the filter exceeds the pumpscapabi
29、lities; that is, the filter becomes clogged.7.8.2 Specific working operations of shorter duration are tobe investigated.7.8.3 Determinations of variations of the exposure during ashift are made.7.9 Attach the sampling head to the worker so that it islocated in the breathing zone. The workers breathi
30、ng zone5The sole source for the 10-mm nylon cyclone calibrating jar known to thecommittee at this time is Fischer Scientific, 711 Forbes Ave. If you are aware ofalternative suppliers, please provide this information to ASTM Headquarters. Yourcomments will receive careful consideration at a meeting o
31、f the responsibletechnical committee1which you may attend.FIG. 1 Example of Personal Sampler for Respirable DustD 4532 97 (2003)2consists of a hemisphere 300-mm radius extending in front ofthe face, and measured from a line bisecting the ears. Thesampling head shall be placed in such a manner to pre
32、vent dustfrom falling into it and to avoid restricting the inlet. The pumpcan be attached to the workers belt.7.10 Initiate sampling by turning the pump on and settingthe flow rate determined in 8.5 and according to the manufac-turers instructions. Record the flow rate and the time. If theflow rate
33、changes during sampling by more than 65 %, recordthe change and the time. Reset the flow rate. If unable to resetthe flow rate to the original setting, terminate sampling andnote the reason for termination. Follow Guide D 6062M forpersonal samplers.7.11 At the end of the sampling period, turn the pu
34、mp offand record the final flow rate and time.7.12 Replace the filter holder caps. Remove the samplingunit from the worker.7.13 For each set of 10 or fewer samples, submit a blanksample. The filters and filter holders to be used as blanks areprepared and transported in the same manner as the samples
35、except that no air is drawn through them. Label these as blanks.7.14 The filter assembly should be returned to the laboratoryin a suitable container designed to prevent sample damage intransit.8. Calibration and Standardization8.1 Air flow calibration of the sampling unit should becompleted before a
36、nd after each sampling session. (See Fig. 3.)Maintenance and repairs, according to the manufacturersinstructions, should be performed on a regular schedule andrecords kept for documentation.8.2 The choice of calibration instrument will depend largelyon where the calibration is to be performed. A soa
37、p bubblemeter or spirometer is recommended. Instructions for calibra-tion of the sampling unit with the soap bubble meter areprovided in 8.3-8.9 and Fig. 3. If a spirometer is selected, anappropriate procedure shall be used. Since the flow rate givenby a pump is dependent on the pressure drop across
38、 thesampling device, for instance the filter and cyclone, the pumpmust be calibrated while operating with a representativesampling head in line. Calibration of the sampling unit shouldFIG. 2 Bias of Three Cyclone Types Relative to the International Respirable Dust Sampling ConventionFIG. 3 Example o
39、f the Calibration Setup for Personal Sampling Pump with Respirable Dust Sampling HeadD 4532 97 (2003)3be performed at approximately the same temperature andpressure that the sample will be collected.8.3 Place the sampling head, with the same type of filter tobe used to collect the sample, in the jar
40、. Connect the samplinghead to the outlet of the jar and connect the outlet of the jar tothe pump to be calibrated.8.4 Turn on the pump and moisten the inside of the bubblemeter by drawing bubbles up the meter until the bubbles areable to travel the entire length of the buret without bursting.8.5 Adj
41、ust the pump to provide the desired flow rate.8.6 Start a soap bubble up the buret and measure with astopwatch the time it takes the bubble to pass from the zero lineto the 1.0 L mark.8.7 Repeat the procedure in 8.5 at least three times. Calcu-late the flow rate by dividing the volume of air between
42、 thepreselected marks of the buret by the time required for the soapbubble to traverse the distance and average the results. If themeasured flow rate is outside the specification, readjust as in8.5 and repeat 8.6 and 8.7.8.8 Record the date of the calibration and the temperatureand pressure at the t
43、ime of the calibration.8.9 Alternatively, the calibrated flow meter (6.9) may beused to field check flow rate at the beginning and end ofsampling. Connect the outlet side of the flow meter to the inlet(vacuum side) of the pump. Connect the inlet side of the flowmeter to the outlet of the jar, which
44、contains the sampling head.Turn on the pump and determine flow rate from a calibrationchart prepared for the flow meter by comparison with a soapbubble flow meter or spirometer.9. Procedure9.1 Carefully swab the outer surface of the filter assemblywith a lintless paper towel moistened with water bef
45、oreopening the filter holder to minimize sample contamination.9.2 Open the filter holder and carefully remove the filterfrom the holder with the aid of a rod inserted into the outlethole of the filter holder and a filter tweezer. Handle the filtersvery gently by the edge to avoid loss of dust. Trans
46、fer the filterto a petri dish. Brush out the filter holder and add to the filterany dust adhering to the inside of the filter holder. Place thefilter in the weighing room. Handle the equilibrated filter asstated in 7.2.9.3 Weigh the filter on the same analytical balance that wasused to determine the
47、 tare weight (6.6).10. Calculation10.1 Mass of dust found on the sample filter:Ms5 m22 m1! 2 m3(1)where:m1= tare weight, in mg, of the clean filter before sampling,m2= the weight, in mg, of the sample-containing filter,m3= the mean value of mass, in mg, found on the blankfilter, andMs= mass found on
48、 the sample filter.10.2 The sampled volume is:Vs 5 Q 3 t/1000 (2)where:Q = the mean indicated flow rate, in L/min of airsampled,t = the sampling time, in min,Vs = the volume, in m3, of the air sampled, and1000 = conversion from L to m3.NOTE 2There are no temperature or pressure corrections for chang
49、esin sampled volume since it is critical that the flow rate required for thecyclone be set at the time and location of sampling.10.3 The concentration of the respirable dust in the sampledair is expressed in mg/m3.C 5 K 3 Ms/Vs(3)where:C = mass concentration of respirable dust,K = a correction factor for the cyclone to convert torespirable mass fraction (supplied by the manufac-turer),Ms= mass, in mg found on the sample filter, see 10.1, andVs= the volume, in m3, of air sampled, see 10.2.11. Precision and Bias11.1 Analytical Range, 0.2 mg to 2 mg per sample.11.2
