1.1 This test method describes the procedures to determine the opacity of a plume, using digital imagery and associated hardware and software. The aforementioned plume is caused by particulate matter emitted from a stationary point source in the outdoor ambient environment.
1.2 The opacity of emissions is determined by the application of a Digital Camera Opacity Technique (DCOT) that consists of a Digital Still Camera, Analysis Software, and the Output Function’s content to obtain and interpret digital images to determine and 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 Conditions that shall be considered when using this method to obtain the digital image of the plume include the plume’s background, the existence of condensed water in the plume, orientation of the Digital Still Camera to the plume and the sun (see Section 8).
1.5 This standard describes the procedures to certify the DCOT, hardware, software, and method to determine the opacity of the plumes.
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
ASTM D7520-16(2023) Referenced Document
ASTM D1356 Standard Terminology Relating to Sampling and Analysis of Atmospheres*, 2024-04-22 Update
ASTM E691 Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
IEEE 12207-2008 Systems and software engineering - Software life cycle processes*, 2024-04-22 Update
ASTM D7520-16(2023) history
2023ASTM D7520-16(2023) Standard Test Method for Determining the Opacity of a Plume in the Outdoor Ambient Atmosphere
2016ASTM D7520-16 Standard Test Method for Determining the Opacity of a Plume in the Outdoor Ambient Atmosphere
2013ASTM D7520-13 Standard Test Method for Determining the Opacity of a Plume in the Outdoor Ambient Atmosphere
2009ASTM D7520-09 Standard Test Method for Determining the Opacity of a Plume in the Outdoor Ambient Atmosphere