1、Designation: D4599 03 (Reapproved 2009)1D4599 14Standard Practice forMeasuring the Concentration of Toxic Gases or VaporsUsing Length-of-Stain Dosimeters1This standard is issued under the fixed designation D4599; the number immediately following the designation indicates the year oforiginal adoption
2、 or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1 NOTEReapproved with editorial changes in October 2009.1. Scope1.1 This practice descri
3、bes the detection and measurement of time weighted average (TWA) concentrations of toxic gases orvapors using length-of-stain colorimetric dosimeter tubes. A list of some of the gases and vapors that can be detected by thispractice is provided in Annex A1. This list is given as a guide and should be
4、 considered neither absolute nor complete.1.2 Length-of-stain colorimetric dosimeters work by diffusional sampling. The results are immediately available by visualobservation; thus no auxiliary sampling, test, nor analysis equipment are needed. The dosimeters, therefore, are extremely simpleto use a
5、nd very cost effective.1.3 The values stated in SI units shall are to be regarded as the standard. No other units of measurement are included in thisstandard.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user
6、 of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1356 Terminology Relating to Sampling and Analysis of Atmospheres2.2 Other Document:3U.S. Occupational Safety and H
7、ealth StandardTitle 29 1910.1000 Subpart Z3. Terminology3.1 DefinitionsFor definitions of terms used in this practice, refer to Terminology D1356.4. Summary of Practice4.1 Length-of-stain colorimetric dosimeters consist of a sealed glass tube containing a detector inside the tube (1-5).4 Thedetector
8、 is a length of granulated material impregnated with a reactive chemical that is sensitive to the particular gas for whichthe dosimeter is designed.To use the tube, one end is opened.The gas, if present, diffuses into the tube and reacts with the chemicalreagent on the carrier material, causing the
9、latter to change color. Each lot of dosimeters is individually calibrated so that bymeasuring the length of stain and the time of exposure, the TWA concentration to which the dosimeter has been exposed can bedeterminedmeasured directly and immediately.4.2 Information on the correct use of length of
10、stain dosimeter tubes is presented.1 This practice is under the jurisdiction of ASTM Committee D22 on Air Quality and is the direct responsibility of Subcommittee D22.04 on Workplace Air Quality.Current edition approved Oct. 1, 2009Sept. 1, 2014. Published December 2009October 2014. Originally appro
11、ved in 1986. Last previous edition approved in 20032009as D4599 03.D4599 03 (2009)1. DOI: 10.1520/D4599-03R09E01.10.1520/D4599-14.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume informati
12、on, refer to the standards Document Summary page on the ASTM website.3 Code of Federal Regulations, available from U.S. Government Printing Office, Washington, DC 20402.Office Superintendent of Documents, 732 N. Capitol St., NW, MailStop: SDE, Washington, DC 20401, http:/www.access.gpo.gov.4 The bol
13、dface numbers in parentheses refer to the list of references appended to this practice.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to
14、 adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Cons
15、hohocken, PA 19428-2959. United States15. Significance and Use5.1 The U.S. Occupational Safety and Health Administration (OSHA) in 29 CFR 1910.1000 Subpart Z designates that certaingases and vapors present in work place atmospheres must be controlled so that their concentrations do not exceed specif
16、ied limits.Other countries have similar regulations.5.2 This practice will provide a means for the determinationmeasurement of airborne concentrations of certain gases and vaporslisted in 29 CFR 1910.1000 and in other countries regulations.5.3 Apartial list of chemicals for which this practice is ap
17、plicable is presented in AnnexA1 with current Threshold Limit Values(TLV)5 (2) and typical measurement ranges for the selected chemicals as obtained from various manufacturersmanufacturersspecifications.5.4 This practice may be used for either personal or area monitoring.6. Interferences6.1 The inst
18、ructions may provide correction factors to be applied when certain interferences are present. Some commoninterfering gases or vapors for each dosimeter are listed in the instruction sheets for the dosimeter provided by themanufacturersmanufacturers.7. Apparatus7.1 Dosimeter Tube:7.1.1 General Descri
19、ptionAlength-of-stain dosimeter tube tube, also called a “colorimetric diffusion tube,” consists of a glasstube containing an inert granular material impregnated with a chemical system that reacts with the gas or vapor of interest. As aresult of this reaction, the impregnated chemical changes color.
20、 The granular material is held in place within the glass tube byporous plugs of a suitable inert material. To protect the contents during storage, the ends of the glass tube are flame sealed. Thecalibration scale is printed on the tube to make it easy to read the length of stain of reacted chemical.
21、7.1.2 Stability on StorageStability on storage may vary depending on manufacturer and type of dosimeter, but most dosimetertubes can be stored for at least 24 months with no deleterious effects.7.2 Tube HoldersDuring use, the dosimeter tube is held in a lightweight, plastic holder. The tube holder p
22、rotects the dosimeterduring use and also helps to minimize effects of air currents on performance. The holder has a clip that allows it to be fastenedto a collar or pocket during personal sampling or to some appropriate object during area sampling.8. Reagents8.1 The reagents used to impregnate the g
23、ranular material in the dosimeters are specific for each tube, and, to detect a specificgas or vapor, may vary from manufacturer to manufacturer. The instruction sheets supplied by the manufacturers usually give theprincipal chemical reaction(s) that occur(s) in the tube.9. Diffusional Sampling Theo
24、ry9.1 FicksFicks First Law of Diffusion states that the mass (m) of material that diffuses is directly proportional to the diffusioncoefficient (D) of the material, the diffusional cross sectional area (A), the concentration gradient (c) and the time (t), andinversely proportional to the length of t
25、he diffusion path (l). These parameters are linked by FicksFicks First Law of Diffusionas follows:dmdt 5DAcl (1)NOTE 1The diffusion coefficient of a molecule is a function of the temperature and the nature of the medium through which it is diffusing.The molecules of the contaminant reach the granula
26、r reagent layer. At this point the chemical conversion to a colored reactionproduct takes place. The increase in length of the color zone dl is proportional to the converted mass of contaminant dm (Eq 12).dl5dmkA (2)where:k = absorption capacity of a layer element, ng/cm3, andA = cross-sectional are
27、a of the reagent layer, cm2 (assumed constant).This process, called chemisorption, has the following effects on the remaining measuring process:9.1.1 Since the gas molecules to be measured are bound chemically, they are practically no longer present in the atmospheredirectly above the granular carri
28、er material. Thus, additional sample molecules are able to flow into the detector tube accordingto FicksFicks First Law of Diffusion, since the concentration gradient c is maintained.5 Threshold Limit Values (TLV) is a registered trademark of the American Conference of Governmental Industrial Hygien
29、ists (ACGIH).D4599 1429.1.2 The effect of the color zone formed in the process is that the subsequent contaminant molecules must cover a longerdiffusion path, l, until they reach the unused reagent layer. This means that the diffusion path, l, as defined in the diffusion law,is not constant, but bec
30、omes greater with progressive exposure. The transport rate dm/dt of the sample molecules decreases in theprocess. The slowdown in mass transport has a direct effect on the shape of the calibration curves of the indicating tubes. Themathematical correlation can be traced to Eq 1 and 2Formulas 1 and 2
31、. . Eliminating the contaminant mass, dm, from Eq 1 and2 and integrating yields:cTWA 1t *0t c dt5S k2Dt D 3l2 (3)where cTWA is the time-weighted average of the time-dependent concentration, c. Calibration curves described by this equationare not linear, but have the shape of a parabola when cTWA is
32、plotted versus l. Accounting for an air gap between tube entranceand sorbent, and also transverse analyte flow (if present), modifies Eq 3 through an additive constant and also a term proportionalto the stain length, l(5).9.1.3 The correlation of Eq 3 is confirmed by actual calibration curves of dif
33、fusion tubes. The influence of the product resultingfrom the concentration c and the measuring duration t on the detector tube indication l is shown in Fig. 1. A linear correlation isobtained between the square of the detector tube indication and the product resulting from the concentration and incr
34、easing timeas shown by Fig. 2.9.2 Measurement RangeThe measurement range of the various length-of-stain dosimeters is shown in Annex A1.9.3 Air VelocityThe sampling rate of the dosimeter tubes is very slow (of the order of 0.1 cm3/min); thus the “starving” effectin static air (for example, face velo
35、cities 0.1 m/sec) is not significant for these devices, so that air velocity is not critical. However,a stream of high velocity air should not be permitted to flow directly into the open end of the tube (parallel to the axis of the tube).The tube holder provides additional protection from turbulence
36、 within the dosimeter.FIG. 1 Dosimeter Calibration Curve Relating Length of Color Zone to Concentration TimeD4599 14310. Sampling with Length-Of-Stain Dosimeter Tubes10.1 GeneralSince these dosimeters work by diffusion, the procedure for using them is very simple. All that is necessary isto open one
37、 end of the dosimeter properly, place the opened tube into its holder, and fasten the holder to an object at a point wherethe sampling is to be done. Follow the instruction sheet of the manufacturer for the proper use of each dosimeter tube.The samplingstarting time and ending time must be recorded
38、so that the sampling time is known. This is needed to estimate the averageconcentration (TWA) over the sampling time.NOTE 2Temperature and HumidityDosimeters should only be deployed under the suggest range of operating conditions by manufacturers.10.2 DeterminingMeasuring the Concentration from the
39、Dosimeter TubeThe dosimeter tubes are calibrated in units ofconcentration time, typically ppm(v) hours. The average gas concentration can be determinedmeasured by the followingformula:average concentration ppmv!# (4)5dosimeter tube reading ppmv!hours#actual sampling time hours#11. Accuracy of Dosime
40、ter Tubes (44 and 5-5)11.1 The accuracy of dosimeter tubes is generally within 625 %; however, some tube types may vary from this, and specifictube accuracy may vary from lot to lot and manufacturer to manufacturer.Therefore, if users want to know the accuracy of a certaintube, they should check wit
41、h the manufacturer for an accuracy statement or run their own tests to determineestimate accuracy undertheir particular conditions of use.12. Keywords12.1 air monitoring; colorimetric dosimeter tubes; diffusional sampling; dosimeter tubes; sampling and analysis; toxic gases andvapors; workplace atmo
42、spheresFIG. 2 Dosimeter Calibration Curve Relating Square of Color Zone Length to Concentration TimeD4599 144ANNEX(Mandatory Information)A1. SOME GASES AND VAPORS THAT CAN BE MEASURED BY LENGTH-OF-STAIN DOSIMETER TUBESREFERENCES(1) Pannwitz, Karl-Heinz, “Direct-Reading Diffusion Tubes,” Drger Review
43、, Vol 53, 1984, pp. 1014.(2) American Conference of Governmental Industrial Hygienists, Threshold Limit Values for Chemical Substances and Physical Agents and BiologicalExposure Indices,2013 2009 (updated annually), Cincinnati, OH.(3) Palmes, E. D., and Lindenboom, R. H., “Ohms“Ohms Law, FicksFicks
44、Law and Diffusion Samplers for Gases,” Analytical ChemistryAnalyticalChemistry, , Vol 51, 1974, pp. 24002401.(4) Roberson, R. W., Matsunobu, K., Hoshino, F., and Komatsu, T.,“Performance T., “Performance Testing of Sensidyne/Gastec Dosimeter Tubes for CO,H2S, SO2 and HCN,” presented at the American
45、Industrial Hygiene Conference (Conference, 1985)TABLE A1.1 Threshold Limit Values (2)NOTE 1The measurement ranges given in the table are not for a singletube. They are the lowest and highest concentrations (over 8 h exposure)by 8-hour exposure listed in the various manufacturersmanufacturersbrochure
46、s.Substance TLVR TWA ValuesA Measurement Range(ppm(v)ppm(v) mg/m3Acetic acid 10 25 0.6325Acetone 500 1187 6.3187.5Ammonia 25 17 2.5187.5Ammonia 25 17 2.5200Butadiene 2 4.4 1.337.5Butadiene 2 4.4 1.340Carbon dioxide 5000 9000 62.537 500Carbon dioxide 5000 9000 0.032500Carbon monoxide 25 29 1.3125Carb
47、on monoxide 25 29 6125Chlorine 0.5 1.5 0.36.3Ethanol 1000 1881 1253125Ethanol 1000B 1884 1253125Ethyl acetate 400 1440 62.51250Ethyl acetate 400 1441 62.51250Formaldehyde C0.3B C0.37B 0.132.5Formaldehyde C0.3C C0.37C 0.132.5Hydrogen chloride C5B C7.5B 1.325Hydrogen chloride C2C C3.0C 1.325Hydrogen c
48、yanide C4.7B C55 1.325Hydrogen cyanide C4.7C C5C 1.325Hydrogen fluoride 0.5 0.41 1.2512.5Hydrogen peroxide 1 1.4 0.635Hydrogen sulfide 10 14 1.337.5Hydrogen sulfide 1 1.4 1.340Methyl ethyl ketone 200 590 2.575Nitrogen dioxide 3 5.6 0.125Nitrogen dioxide 0.2 0.38 1.325Olefin . . 12.5250Perchloroethyl
49、ene 25 170 3.1187.5Perchloroethylene 25 170 3.1200Sulfur dioxide 2 5.2 0.618.8Sulfur dioxide 0.25B 0.66 0.319Toluene 50 188 12.5250Toluene 20 75 2.5380Trichloroethylene 50 269 3.1125Trichloroethylene 10 54 3.1125Water vapor . . 0.6312.5 mg/lA Values for ppm(v) and mg/m3 are Time-Weighted Average (TWA).(TWA) (8 hr).B Threshold limit value-Short-Term Exposure Limit (15 min).C C = Ceiling limit.Threshold limit value-Ceiling.D4599 145(5) Bartley, D. L., “Diffusive Samplers Using Lon
