Opacity

Term · Environment · MLC-T-ENV-019611

1. The amount of light obscured by particulate pollution in the air; clear window glass has zero opacity, a brick wall is 100 percent opaque. Opacity is an indicator of changes in performance of particulate control systems.

2. Quality of papers that defines its opaqueness or ability to prevent two-sided printing from showing through.

3. The amount of light obscured by particulate matter in the air.

4. Degree to which emissions reduce the transmission of light and obscure the view of an object in the background. [40 CFR 60.2 (CFR 2013)] [40 CFR 63.11237 (CFR 2013)][40 CFR 72.2 (CFR 2013)]

5. Degree to which emissions reduce the transmission of light. [40 CFR 63.1459 (CFR 2013)]

6. Fraction of a beam of light, expressed in percent, which fails to penetrate a plume of smoke.

7. Fraction of a beam of light, expressed in percent, which fails to penetrate a plume of smoke as measured and calculated under the provisions of subpart B of this part.

8. Fraction of a beam of light, expressed in percent, which fails to penetrate a plume of smoke, as measured by the procedure specified in § 1033.525.

9. Fraction of a beam of light, expressed in percent, which fails to penetrate a plume of smoke, as measured by the procedure specified in § 1039.501.

10. Degree to which emissions reduce the transmission of light and obscure the view of an object in the background. For continuous opacity monitoring systems, opacity means the fraction of incident light that is attenuated by an optical medium.

11. Degree to which emissions reduce the transmission of light and obscure the view of an object in the background.

Table 1. Record
Identifier	MLC-T-ENV-019611
Field	Environment
Subject	Air
References	Terms of Environment; Communications Stylebook Glossary; I-BEAM Glossary of Terms; 40 CFR 49.10711 (CFR 2013); 40 CFR 63.1459 (CFR 2024); 40 CFR 89.2 (CFR 2013); 40 CFR 86.082-2 (CFR 2018); 40 CFR 92.2 (CFR 2013); 40 CFR 1033.901 (CFR 2013); 40 CFR 1039.801 (CFR 2013); 40 CFR 49.123 (CFR 2013)

Record as JSON

{
  "id": "MLC-T-ENV-019611",
  "term": "Opacity",
  "field": "Environment",
  "definition": "1. The amount of light obscured by particulate pollution in the air; clear window glass has zero opacity, a brick wall is 100 percent opaque. Opacity is an indicator of changes in performance of particulate control systems.\n\n2. Quality of papers that defines its opaqueness or ability to prevent two-sided printing from showing through.\n\n3. The amount of light obscured by particulate matter in the air.\n\n4. Degree to which emissions reduce the transmission of light and obscure the view of an object in the background. [40 CFR 60.2 (CFR 2013)] [40 CFR 63.11237 (CFR 2013)][40 CFR 72.2 (CFR 2013)]\n\n5. Degree to which emissions reduce the transmission of light. [40 CFR 63.1459 (CFR 2013)]\n\n6. Fraction of a beam of light, expressed in percent, which fails to penetrate a plume of smoke.\n\n7. Fraction of a beam of light, expressed in percent, which fails to penetrate a plume of smoke as measured and calculated under the provisions of subpart B of this part.\n\n8. Fraction of a beam of light, expressed in percent, which fails to penetrate a plume of smoke, as measured by the procedure specified in § 1033.525.\n\n9. Fraction of a beam of light, expressed in percent, which fails to penetrate a plume of smoke, as measured by the procedure specified in § 1039.501.\n\n10. Degree to which emissions reduce the transmission of light and obscure the view of an object in the background. For continuous opacity monitoring systems, opacity means the fraction of incident light that is attenuated by an optical medium.\n\n11. Degree to which emissions reduce the transmission of light and obscure the view of an object in the background.",
  "subject": "Air",
  "references": [
    "Terms of Environment",
    "Communications Stylebook Glossary",
    "I-BEAM Glossary of Terms",
    "40 CFR 49.10711 (CFR 2013)",
    "40 CFR 63.1459 (CFR 2024)",
    "40 CFR 89.2 (CFR 2013); 40 CFR 86.082-2 (CFR 2018)",
    "40 CFR 92.2 (CFR 2013)",
    "40 CFR 1033.901 (CFR 2013)",
    "40 CFR 1039.801 (CFR 2013)",
    "40 CFR 49.123 (CFR 2013)"
  ],
  "url": "https://mlchart.com/terminology/environment/opacity/"
}

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