1、Designation: E1260 03 (Reapproved 2015)Standard Test Method forDetermining Liquid Drop Size Characteristics in a SprayUsing Optical Nonimaging Light-Scattering Instruments1This standard is issued under the fixed designation E1260; the number immediately following the designation indicates the year o
2、foriginal adoption 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.INTRODUCTIONThis standard is one of several describing a different cla
3、ss of test methods for determining liquiddrop size characteristics in a spray. These test methods can be broadly distinguished as “optical” or“non-optical.” In the optical category there are test methods that essentially make images (such asphotographs) of drops that can be measured either manually
4、or automatically, and test methods thatdo not make images but use optical phenomena exhibited by single drops or ensembles of drops whichcan be recorded and used to calculate either individual drop sizes or the distribution of drop sizes inan ensemble. This test method deals with the latter class, a
5、nd hence, is described as “nonimaging.” Thevarious optical phenomena involved are commonly described as “light-scattering.” Using any of thesetest methods, the spray is observed for a period of time during which a large number of drops isexamined, and the data are treated so as to derive drop-size s
6、tatistics for the sample investigated.1. Scope1.1 The purpose of this test method is to obtain data whichcharacterize the sizes of liquid particles or drops such as areproduced by a spray nozzle or similar device under specifiedconditions using a specified liquid. The drops will generally bein the s
7、ize range from 5-m to the order of 1 000-m diameter;they will occur in sprays which may be as small as a few cubiccentimetres or as large as several cubic metres. Typically thenumber density of the particles can vary significantly from onepoint to another.1.2 This test method is intended primarily f
8、or use instandardizing measurements of the performance of spraypro-ducing devices. It is limited to those techniques and instru-ments that operate by passing a beam of light through the sprayand analyzing the light scattered by the droplets to derive sizeinformation. Such techniques do not produce i
9、mages of indi-vidual drops, and therefore, are known as “optical (nonimag-ing) instruments.”1.3 The measurements made, when referred to the entirespray being sampled, may be flux sensitive or spatial, asdefined in Practice E799, depending on the techniques usedwith a particular instrument.1.4 This s
10、tandard 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 establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.
11、1 ASTM Standards:2E177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE456 Terminology Relating to Quality and StatisticsE799 Practice for Determining Data Criteria and Processingfor Liquid Drop Size AnalysisE1088 Definitions of Terms Relating to Atomizing Devices(Withdrawn 1997
12、)3E1296 Terminology for Liquid Particle Statistics (With-drawn 1997)3E1620 Terminology Relating to Liquid Particles and Atomi-zation2.2 NFPA Standards:NFPA 30 Flammable and Combustible Liquids Code41This test method is under the jurisdiction of ASTM Committee E29 on Particleand Spray Characterizatio
13、n and is the direct responsibility of Subcommittee E29.02on Non-Sieving Methods.Current edition approved March 1, 2015. Published March 2015. Originallyapproved in 1988. Last previous edition approved in 2009 as E1260 03 (2009).DOI: 10.1520/E1260-03R15.2For referenced ASTM standards, visit the ASTM
14、website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.4Available from National
15、 Fire Protection Association (NFPA), 1 BatterymarchPark, Quincy, MA 02169-7471, http:/www.nfpa.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1NFPA 33 Spray Application Using Flammable and Combus-tible Materials43. Terminology3.1
16、DefinitionsFor terminology pertaining to this testmethod, refer to Terminology E456, Practice E799, DefinitionsE1088, and Terminology E1296.3.2 Definitions of Terms Specific to This Standard:3.2.1 spraythe term “spray” in this test method includesall ensembles, arrays, or clouds composed of liquid p
17、articles ordrops whether produced artificially or naturally. Although it isusual to consider a spray as implying significant motion of thedrops relative to the atmosphere there are situations in whichthe relative velocity is or becomes sufficiently low to benegligible. In this case, a “spray” is ind
18、istinguishable from a“cloud” which implies a static ensemble of drops.4. Summary of Test Method4.1 The spray is examined by a means whereby a beam oflight passes through local regions, which make a representativesample, and one of the forms of light-scattering phenomenathat occur is detected by the
19、instrument. The data are recorded,usually by data-processing equipment, and are transformedmathematically into statistics characterizing the size distribu-tion These operations may be performed manually or automati-cally and the instrument may provide a visual display or aprinted report.5. Significa
20、nce and Use5.1 The purpose of this test method is to provide data onliquid drop-size characteristics for sprays, as indicated byoptical nonimaging light-scattering instruments. The resultsobtained generally will be statistical in nature. The number ofvariables concerned in the production of liquid s
21、pray, togetherwith the variety of optical, electronic, and sampling systemsused in different instruments, may contribute to variations inthe test results. Care must be exercised, therefore, whenattempting to compare data from samples obtained by differentmeans.6. Interferences6.1 Spray NozzleMany sp
22、ray nozzles are designed withinternal liquid passages of small dimensions and it is importantto ensure that these passages do not become blocked withforeign matter. Some nozzles have built-in filters or screens butin all cases it is advisable to fit a filter in the liquid supply lineimmediately upst
23、ream of the nozzle inlet to remove any solidparticles that are considered likely to cause problems.6.1.1 The use of one liquid to simulate another fuel mayaffect the performance of certain types of nozzle due todifferences in density, viscosity, and surface tension. Inaddition, however, occasionally
24、 a problem may occur due todifferences in wetting the surfaces, for example, a nozzle testedpreviously in fuel (or other hydrocarbon) may exhibit a poorquality spray when first tested with water and may require theuse of a degreasing agent to remove traces of hydrocarbonfrom the surfaces containing
25、the liquid.6.1.2 It is very important to protect the edges of thedischarge orifice of a spray nozzle from accidental damageprior to testing. This protection is best accomplished by the useof a cover over the discharge orifice of the nozzle duringstorage and installation on the test stand.6.2 Care mu
26、st be exercised to prevent the ingress of liquiddrops into the instrument. The surfaces of lenses, mirrors, andwindows should be inspected at frequent intervals for cleanli-ness or damage and the manufacturers recommendationsfollowed.7. Apparatus7.1 Light Source, (including lasers),7.1.1 Optical Mea
27、ns, for producing a suitable beam thatpasses through a region of the spray,7.1.2 Detecting Means, for recording light-scattering phe-nomena resulting from the liquid drops and means for trans-forming the observations into statistical estimates of drop sizeand dispersion characteristics, as shown in
28、Fig. 1.7.2 Spray Chamber, preferably without components thatcould affect the optical behavior of the incident/scattered light(or have known effect thereon). It is convenient to employ thiswhen the spray or spray-producing device to be tested is smallin size relative to the apparatus. Use of this cha
29、mber may bedesirable to protect the optical and electronic components ofthe apparatus from damage by the liquid spray (see alsoSection 8). In this case the apparatus is preferably securelyinstalled in a suitable location. The chamber should not affectthe normal formation of the spray.7.2.1 In cases
30、where there are known or suspected steepdrop concentration gradients or variations in the spray, forexample, in hollow-cone spray patterns, means shall be pro-vided for accurately locating the spraying device relative to thelight beam source and sensor. Provision should also be madefor selectively e
31、xamining a number of different locations orregions in the spray.FIG. 1 Diagram of Test ArrangementE1260 03 (2015)27.3 Operating instructions shall be supplied by the manu-facturer or contractor of the apparatus or instrument. Theinstructions shall contain:7.3.1 Description of the operational princip
32、les of theinstrument, oriented towards a trained technical operator.Reference to relevant published literature shall be included;7.3.2 Recommendations for installation and use of theapparatus;7.3.3 Range of ambient temperature, humidity, and linevoltage variation, and any known limitations on the op
33、eratingenvironment;7.3.4 Ranges of liquid particle size, velocity, and numberdensity or some equivalent parameter for which the instrumentis designed;7.3.5 Maintenance procedures recommended and required;7.3.6 Calibration verification procedures; and7.3.7 Statement of accuracy, repeatability, and re
34、producibil-ity of the resultant drop-size data.8. Hazards8.1 Safety Precautions:8.1.1 WarningA spray of flammable liquid dispersed inair presents the risk of explosion and fire. Refer to NFPA 30 orNFPA 33 for information about safe practices for storage andhandling of flammable liquids and for spray
35、 processes involv-ing sprays of flammable liquids.8.1.2 WarningExposure to drops of various liquids byinhalation, ingestion, and skin contact, may constitute healthhazards.8.1.3 WarningEmission of some sprayed liquids into theatmosphere may be harmful to the environment or may pose ahealth risk.8.1.
36、4 WarningLaser-based instruments contain lasers orother strong light sources which may pose a hazard to personsin their vicinity.8.1.5 Always read and follow the label, federal, state, andlocal guidelines for the handling, application, and disposal ofchemicals, and manufacturer instructions for inst
37、rument use.8.2 Containment is normally required.8.3 Additional hazards may need to mitigated or avoided.9. Sampling9.1 For purposes of this test method each discrete test isconsidered a sample. If the duration of the test observationperiod is sufficiently long the sample may be regarded astime-avera
38、ged data for a large number of liquid particles for theparticular location in the spray. In this case there may be noneed for repetitive (replicated) tests.9.2 If the test objective is to obtain measurements asrepresentative as possible of the entire spray, then the samplinglocations shall be chosen
39、 to accomplish this purpose. If largedrop concentration gradients are apparent or detected inpreliminary tests, a sufficient number of sampling locationsshall be selected to allow an averaging procedure to beemployed.9.3 Where previously observed data exist relative to thedevice under test or where
40、operating circumstances dictate itshall be permissible to take observations at a single location inthe spray and to report the result as a “standardized represen-tative determination.”9.4 In most instances, measurements at a single location arenot sufficient, so the spray should usually be traversed
41、 laterally,longitudinally, or axially, depending upon individual require-ments. The number of points to be tested should ensure that astatistically representative sample of the spray is made.10. Preparation of Apparatus10.1 Use of this test method requires that the presence of theinstrument, or any
42、portions thereof, in proximity to the sprayshall not interfere with the process of producing the spray (byatomization of the liquid) or the air patterns in the region beingexamined. This technique is described as “nonintrusive.”10.2 The instruments are invariably designed and calibratedto provide eq
43、uivalent spherical diameters for particles. Theinstruments may be fully automatic in the sense that theyproduce a printed report of the results of each test, or they mayrequire manual processing of the data observed. In any case theindividuals performing the test methods are required to usejudgment
44、in aligning the light beam in relation to the spray inaccordance with established procedures for each subject. Theseprocedures may include multiple positions in the spray, repli-cation of tests, and other averaging techniques.10.3 Liquid particles may change size, for example, due toevaporation. Fur
45、thermore, breakup of liquids from jets orsheets into particles changes as the particles travel from theirsource. The test procedure must take these factors into accountby recognizing the need for sufficient distance from the originof the spray for atomization to be essentially complete. For thisreas
46、on an instrument that requires dilution of a sample of thespray (by adding air, for example) in order to reduce theeffective drop concentration may not be suitable for use withvolatile liquids.10.4 The physical size or shape of the spray nozzle presentsno special problem provided the spray is visibl
47、e and accessibleto the light beam. The shape and size of the spray, however,must be considered in relation to the view volume of the opticalsystem employed.11. Calibration Verification11.1 Optical nonimaging instruments and systems in generalhave optical or electronic components, or both, which nece
48、s-sitate validation of the overall instrument. A periodic check orverification of the performance of the instrument using par-ticles or particle images shall be performed.11.2 Unlike the solid particle situation there is no way ofpreserving a sample of liquid drops in spray form, so at thistime ther
49、e is no primary standard available.11.3 In the absence of primary reference sprays, the follow-ing secondary reference methods are available:11.3.1 A monodisperse droplet generator,11.3.2 Solid beads or particles, and11.3.3 Reticles or graticules.E1260 03 (2015)311.4 Apreserved spray nozzle also may be used periodicallyas an approximate check on the operation of the system whenproviding a carefully defined reference spray.12. Conditioning12.1 In many cases the spray-producing devices to be testedwill have been designed to operate with specific liquids. Thesemay be of an
