1、Designation: D7520 13D7520 16Standard Test Method forDetermining the Opacity of a Plume in the Outdoor AmbientAtmosphere1This standard is issued under the fixed designation D7520; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、 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. Scope1.1 This test method describes the procedures to determine the opacity of a plume, using digital imagery and asso
3、ciatedhardware and software. The aforementioned plume is caused by particulate matter emitted from a stationary point source in theoutdoor ambient environment.1.2 The opacity of emissions is determined by the application of a Digital Camera Opacity Technique (DCOT) that consists ofa Digital Still Ca
4、mera, Analysis Software, and the Output Functions content to obtain and interpret digital images to determineand report plume opacity.1.3 This method is suitable to determine the opacity of plumes from zero (0) percent to one hundred (100) percent.1.4 This test method is not applicable to stacks wit
5、h internal diameters greater than 7.0 ft (2.13 m).21.4 Conditions that shall be considered when using this method to obtain the digital image of the plume include the plumesbackground, the existence of condensed water in the plume, orientation of the Digital Still Camera to the plume and the sun (se
6、eSection 8).1.5 This standard describes the procedures to certify the DCOT, hardware, software, and method to determine the opacity ofthe plumes.1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this stan
7、dard 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 AtmospheresE691 Practice for Conducting an Interlaboratory Study to Determ
8、ine the Precision of a Test Method2.2 U.S. Environmental Protection Agency (USEPA) Document:3USEPA Method 9 Visual Determination of the Opacity of Emissions from Stationary Sources, 40 CFR, Part 60, Appendix A-42.3 Institute of Electrical and Electronics Engineers (IEEE) Document:4IEEE 12207-2008 Sy
9、stems and Software EngineeringSoftware Life Cycle Processes (ISO/IEC 12207:2008(E), Edition: 2nd,Institute of Electrical and Electronics Engineers, 01-Feb-2008, 138 pages, ISBN: 97807381566372.4 Japanese Electronic and Information Technology Industries Association (JEITA) Document:Exchangeable Image
10、 File Format (EXIF) for Digital Still Cameras:Cameras Joint Photographic Experts Group: JPEG file formatversion 2.21, JEITA CP-3451-1 (English version) dated 2003-09; 2003-09http:/www.jeita.or.jp/english/standard/list/list.asp?cateid=1 (b) produces opacity measurements from the combination of human
11、interaction, openor proprietary calculations and algorithms, and image content viewing; (c) and then output said opacity measurement along withAnalysis Softwares configuration, image source documentation and other environmental parameters.3.2.2 certifiedfor the purpose of this standard, certified re
12、fers to achieving or excelling the requirements described in thismethod.3.2.3 DCOT certification packagefor the purpose of this standard, certification package refers to 300 images (150 whitesmoke and 150 black smoke) captured against at least two different backgrounds.3.2.4 DCOT operatorrefers to t
13、he human operating the DCOTsystem who records the digital still images with the Digital StillCamera and then determines plume opacity with the Analysis Software.3.2.5 Digital Still Cameraan image capture device used to collect store and forward digital still images to the AnalysisSoftware for analys
14、is as defined by the DCOT vendors certification documentation.3.2.6 image transfer filean electronic file that contains the image captured by the Digital Still Camera and its associatedenvironment documentation that is consistent with EXIF 2.1 JPG (or higher) format and is input to the Analysis Soft
15、ware. All ofthe digital images obtained by a DCOT system shall be reviewed by a qualified human DCOT operator to assess if the digitalimages are acceptable (for example, no obvious errors in the digital images).3.2.7 opacitymeasurement of the degree to which particulate emissions reduce the intensit
16、y of transmitted photopic light andobscure the view of an object through an effluent gas stream of a given path length in ambient air.3.2.8 opacity sourceany source that produces emissions that are visible to the human eye.3.2.9 output functionhuman readable information documenting the image being a
17、nalyzed and configuration of the AnalysisSoftware used, the opacity measurement and the other required environment variables defined (for example, view angle, winddirection).3.2.10 runFor the purpose of this standard, run or smoke school run refers to 50 consecutive images (25 white and 25 black).Sm
18、oke schools identify Runs with a number (normally 1-10),110), a date, and a location. Smoke schools may allow certificationbetween numbered runs (that is, black smoke from Run 1, and white smoke from Run 2.)4. Summary of Test Method4.1 A Digital Still Camera is used to capture a set of digital image
19、s of a plume against a contrasting background. Each imageis analyzed with software that determines plume opacity by comparing a user defined portion of the plume image where opacityis being measured in comparison to the background providing the contrasting values. The Analysis Software is used to av
20、eragethe opacities from the series of digital images taken of the plume over a fixed period of time. The software is also used to archivethe image set utilized for each opacity determination including the portion of each image selected by the operator.4.2 The following conditions must be followed to
21、 make a valid opacity determination:4.2.1 The image must be captured in a JPEG format that adheres to the EXIF 2.1 (or higher) standard.4.2.2 The image must be captured with the sun located behind the Digital Still Camera and within a 140 sector directly behindthe Digital Still Camera (see Table 1 f
22、or schematic).4.2.3 The image must be captured perpendicular to the direction of plume travel.4.2.4 The ambient light must be sufficient to show a clear contrast between the plume and its background.4.2.5 The portion of the plume selected for opacity determination shall not contain condensed water v
23、apor.4.2.6 The selected portions of each image representing the visible plume and the uniform background must contrast sufficientlyfor the software to differentiate between the plume and its background.4.2.7 The portion of the plume selected for opacity determination shall represent the part of the
24、plume with the highest apparentopacity, excluding water vapor, as determined by the DCOT operator.4.2.8 The area of the digital image to be analyzed for opacity shall be centered in the digital image when taking the photograph.4.2.9 Each DCOT vendor shall provide training for operators of their DCOT
25、 system. The training shall include the content ofthe “Principles of Visual Emissions Measurements and Procedures to Evaluate those Emissions Using the Digital Camera OpticalTechnique (DCOT)” (Annex A1) and a description of how to operate that specific DCOT system that passed smoke school.5. Signifi
26、cance and Use5.1 Air permits from regulatory agencies often require measurements of opacity from stationary air pollution point sources inthe outdoor ambient environment. Opacity has been visually measured by certified smoke readers in accordance with USEPA(USEPA Method 9). DCOT is also a method to
27、determine plume opacity in the outdoor ambient environment.D7520 1625.2 The concept of DCOT was based on previous method development using Digital Still Cameras and field testing of thosemethods.7,8 The purpose of this standard is to set a minimum level of performance for products that use DCOT to d
28、etermine plumeopacity in ambient environments.7 Du, K., Rood, M. J., Kim, B. J., Kemme, M. R., Franek, B. J., and Mattison, K., Quantification of Plume Opacity by Digital Photography, Environmental Science digital image; digital still camera; opacityANNEXES(Mandatory Information)A1. PRINCIPLES OF VI
29、SUAL EMISSIONS MEASUREMENTS AND PROCEDURES TO EVALUATE THOSE EMISSIONS US-ING DIGITAL CAMERA OPTICAL TECHNIQUE (DCOT)A1.1 AbstractA1.1.1 This document was developed to provide background information pertaining to the principles of visual emissionmeasurement, United States Environmental Protection Ag
30、ency (USEPA) Reference Method 9 requirements, ASTM StandardPractice for Competence ofAir Emission Testing Bodies, equipment needed to collect visual emission data for the Digital CameraOptical Technique (DCOT), documentation needed when measuring visual emissions with DCOT, and the certification and
31、duration of certification of DCOT. DCOT was developed as a possible alternative to Method 9 and this document providesbackground information about Method 9 that is also applicable to DCOT.A1.1.2 Anote about terminology: the term “observer” is used in this document when referring to Method 9 to descr
32、ibe the personwho is making a visual emission evaluation to determine plume opacity. However, “observer” is replaced with “Digital StillCamera” when referring to DCOT as the means to record digital still images that are then used to determine plume opacity. Theterm “operator” is used when referring
33、to DCOT to describe the operation of the Digital Still Camera that obtains the digital stillimages and the collection of supporting documentation that are needed to provide a complete dataset for DCOTto determine plumeopacity.A1.1.3 An extensive amount of the information provided below is from the s
34、tudent manual for the “Visible Emission EvaluationProcedures Course,” Air Pollution Training Institute (APTI) Course 325, Final Review Draft (January 1995). The principal authorof the student manual is Thomas H. Rose with style and editing by Monica L. Loewy.TABLE 3 BiasOpacity Level Bias, % of read
35、ing0 NAA5 -7 %10 0 %15 0 %20 0 %25 -5 %30 -4 %35 -5 %40 0 %45 6 %50 0 %55 -3 %60 -3 %65 -5 %70 0 %75 -5 %80 1 %85 4 %90 3 %95 0 %100 NAAA NA is utilized in Table 3 because 0-100 is the range of acceptable values. Onecannot attain a number 100.Assuch the values for bias at 0 and 100 are not applicabl
36、e.D7520 168A1.2 Table of ContentsAbstract A1.1Table of Contents A1.2List of Figures A1.3Principles of Visual Emissions Measurement A1.4Ringelmann Method A1.4.1Equivalent Opacity A1.4.2Opacity and Transmission of Light A1.4.3Light and Particles A1.4.4Absorption A1.4.5Scattered Light A1.4.6Rayleigh Sc
37、attering A1.4.7Mie Scattering A1.4.8Particle Size A1.4.9Variables Influencing Opacity Observations A1.4.10Selecting the Background A1.4.11Method 9 Requirements A1.5Method 9 A1.5.1The Reference Method is one of Observation A1.5.2Opacity Variances A1.5.3Changes in USEPA Procedures A1.5.4Analysis of Er
38、ror A1.5.5Averaging was Introduced to Increase Accuracy A1.5.6Sun Position became an Issue A1.5.7Slant-Angle Considerations were Introduced A1.5.8The Issue of Steam Source Plumes was Introduced A1.5.9Smoke Generators were Standardized A1.5.10Minor Changes to the Method A1.5.11Appearance and Controll
39、able Observational Variables A1.5.12Appearance and Uncontrollable Observational Variables A1.5.13High-Contrast Backgrounds A1.5.14Low-Contrast Backgrounds A1.5.15Positive Error Defined A1.5.16Positive Observational Error A1.5.17Principle A1.5.18Applicability A1.5.19Procedures A1.5.20Observer Positio
40、n Relative to the Sun Notes A1.5.21Observer Line of Sight A1.5.22Multiple Stacks A1.5.23Field Records A1.5.24Observation Point in the Plume A1.5.25Attached Steam Plumes A1.5.26Detached Steam Plumes A1.5.27Recording Observations A1.5.28Data Reduction A1.5.29Calculation of Opacity A1.5.30General Certi
41、fication Requirements A1.5.31Period of Certification A1.5.32Introduction to Digital Camera Opacity Technique (DCOT) A1.6Equipment to Determine Plume Opacity in the Field UsingDigital Camera Opacity TechniqueA1.7Introduction A1.7.1Digital Camera Opacity Technique (DCOT) A1.7.2Tripod A1.7.3Timer/Watch
42、 A1.7.4Direction Finder A1.7.5Rangefinder A1.7.6Clinometric Devices A1.7.7Anemometer A1.7.8Relative Humidity Sensor A1.7.9Documentation Needed to Determine Plume Opacitywith DCOTA1.8Company Name and Location A1.8.1Test Identification Number and Date A1.8.2Type and Operational Status of the Facility,
43、 ProcessUnit and Control DeviceA1.8.3Height of Emission Point and Estimation Method A1.8.4Description of Operator, DCOT and Digital Still Camera A1.8.5Source Layout Sketch A1.8.6Clock Time A1.8.7Cameras Location A1.8.8Environmental Conditions A1.8.9Plume Description A1.8.10Additional Information A1.
44、8.11Operators Signature and Date A1.8.12D7520 169Certification of DCOT A1.9Testing Requirements A1.9.1Grading A1.9.2Certification of DCOT and Certification Period A1.9.3Knowledgeable Users A1.10Testing Requirements A1.10.1Grading A1.10.2Certification of Digital Still Camera Operators A1.10.3A1.3 Lis
45、t of FiguresRingelmann Chart Fig. A1.1Electromagnetic Spectrum Fig. A1.2Dependence of Slant Angle on Distance between the Observerand PlumeFig. A1.3Orientation of the Observer to the Plume and Sun Fig. A1.4Effect of Slant Angle on Path Length and Apparent Opacity Fig. A1.5Card-Type and Needle-Type C
46、ompasses Fig. A1.6Sling Psychrometer Fig. A1.7Slant-Angle Determination Fig. A1.8A1.4 Principles of Visual Emissions MeasurementThis section describes concepts related to opacity and discusses the scientificprinciples associated with measuring opacity and the practical application of those principle
47、s.A1.4.1 Ringelmann Method:A1.4.1.1 Evaluation of visible emissions evolved from a concept developed by Maximillian Ringelmann during the late 1800s.Ringelmann used a chart of calibrated black grids on a white background to measure dark or black smoke emissions from coal-firedboilers. The grids rang
48、ed from approximately 20 % ink coverage for a Ringelmann #1 through 100 % ink coverage, or solid black,for a Ringelmann #5 (Fig. A1.1). The observer then compared the shade of the smoke with the shade of the card.FIG. A1.1 Ringelmann ChartD7520 1610A1.4.2 Equivalent Opacity:A1.4.2.1 During the early
49、 1950s, the Ringelmann concept was expanded to include colors of smoke other than black byintroducing “equivalent opacity.” Equivalent opacity is the opacity equivalent to the obscuring power of black smoke characterizedby a specific Ringelmann grid. Thus, Ringelmann #1 was equivalent to 20 % opacity.A1.4.2.2 United States Environmental Protection Agency (USEPA) discontinued using Ringelmann numbers with USEPAsReference Method 9 procedures for New Source Performance Standards (NSPS).Although current procedures are based solely onopacity, some state regulat
