1、ASTM DL704M 95 0759530 0555033 761 AMERICAN SOCIETI FOR TESTING AND MATERIALS 191 6 Race St.Philadelphia,Pa 19103 Reprinted from the Annual Book of ASTM Standards Copyright ASTM If not listed in the current combined index will appear in the neb edition Designation:D 1704M-95 METRIC Standard Test Met
2、hod for Determining the Amount of Particulate Matter in the Atmosphere by Measurement of the Light Absorbance of a Filter Sample Metric This standard is issued under the fixed designation D 1704M;the number immediately following the designation indicates the year of original adoption or,in the case
3、of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.A superscript epsilon(e)indicates an editorial change since the last revision or reapproval.1.Scope 1.1 This test method measures a function of the concen-tration of suspended particulate matter in th
4、e ambient atmospheres quickly and inexpensively.Hourly repetitive samples are taken automatically.1.2 This test method does not provide results in mass/volume units but in a method-defined unit,dust coefficient per km(DJkm),which is directly related to the soiling effect of the sampled atmosphere wh
5、en drawn through filter paper.Relations between DJkm and mass concentration measure-ments are dependent on the nature,size distribution,shape,and refractive index of the particulate matter.When these factors are constant at one site,a useful relationship between DJkm and mass concentration values ca
6、n often be devel-oped.1.3 The test method can accommodate low and high concentrations of suspended particulate matter by alteration of the sample volume via flow rate or sampling time changes.1.4 The test method is not applicable when fog or mist are present in the sampled atmosphere because wet fil
7、ter paper has a flow resistance so high that the sample pump will not be able to draw sample air through the paper.1.5 The transfer of the sample from the atmosphere to the instrument will precipitate some of the particulate matter on the wails of the tubing used.Guidelines to minimize this effect a
8、re included below,but the test method is limited to situations in which a short sampling line,that is,less than 5 m,can be provided.1.6 The accuracy,reproducibility,and usefulness of this and other test methods for measurements of suspended particulate matter in the ambient atmosphere are limited se
9、verely by the absence of primary calibration standards(“standard dirty air”),and by the characterization of a complex and variable material,suspended particulate matter,by a single property(soiling effect,mass per volume,etc.).These limitations should be borne in mind constantly when a test method i
10、s selected and results from it are evaluated.1.7 This test method is not designed to be used for industrial hygiene monitoring in the absence of other more specific monitoring test methods.1.8 A complete ft-lb companion to Test Method D 1704M has been developed,D 1704.See Annex Al for conversion of
11、data from one test method to the other.1.9 This standard does not purport to address all o f the safety concerns,if any,associated with its use.It is the responsibility o f the user o f this standard to establish appro-priate safety and health practices and determine the applica-bility o f regulator
12、y limitations prior to use.2.Referenced Documents 2.1 ASTM Standards:D 1071 Test Methods for Volumetric Measurement of Gaseous Fuel Samples2 D 1356 Terminology Relating to Sampling and Analysis of Atmospheres3 D 1357 Practice for Planning the Sampling of the Ambient Atmosphere3 D 363 1 Test Methods
13、for Measuring Surface Atmospheric Pressure3 D4096 Test Method for Determination of Total Sus-pended Particulate Matter in the Atmosphere(High-Volume Sampler Method)3 E 1 Specification for ASTM Thermometers4 E 11 Specification for Wire-Cloth Sieves for Testing E 1 3 1 Terminology Relating to Molecula
14、r Spectroscopy6 Purposes5 3.Terminology method,refer to Terminologies D 1356 and E 131.3.1 Definitions-For definitions of terms used in this test 3.2 Descriptions o f Terms SpeciJc to This Standard:3.2.1 absorbance-the logarithm(to base ten)of the ratio of the intensities of light passing through cl
15、ean filter paper to the same filter paper upon which a spot of particulate matter has been collected.The term is then used to refer to the absorbance of the spot.3.2.2 dust coeficient per km(Dam)-the absorbance,multiplied by 100,of a spot of particulate material collected by filtration from the atmo
16、sphere on filter paper,normalized to the length,in km,of a right cylinder of air having a volume equal to that of the air sampled and a cross-section equal in area to the spot.This test method is under the jurisdiction of ASTM Committee D-22 on Sampling and Analysis of Atmospheres and is the direct responsibility of Subcommittee D22.03 on Ambient Atmospheres and Source Emissions.Current edition approved Jan.15,1995.Published March 1995.Onginally published as D 1704M-93.Last previous edition D 17
