| Victoria M. Trasko - Industrial hygiene - 1954 - 344 pages
...designated as No. 2 of the Ringelmann chart, as published by the United States Bureau of Mines, (b) of such opacity as to obscure an observer's view to a degree equal to or greater than the smoke described in Subsection (a) of this section"; further prohibits the "discharge from any source... | |
| Air - 1963 - 474 pages
...designated as No. 2 on the Ringelmann Chart, as published by the United States Bureau of Mines, or (fe) Of such opacity as to obscure an observer's view to...or greater than does smoke described in subsection (я) of this section. Directly involved was subdivision (b] relative to opacity of emission. The Appellate... | |
| United States. Congress. Senate. Committee on Public Works - 1964 - 1418 pages
...duration in any one hour F* is as dark or darker than Ringelmann No. 2 or, of such opacity as to mre an observer's view to a degree equal to, or greater than does smoke «rk as Ringelmann No. 2. t Tfce Department shall, in addition to powers and duties elsewhere têt... | |
| Robert A. Taft Sanitary Engineering Center - Air - 1965 - 142 pages
...designated as No. 2 on the Rlngelmaim Chart, as published by the United States Bureau of Mines, or b. Of such opacity as to obscure an observer's view to...than does smoke described in subsection (a) of this Rule. -13IV. Applicability A. Sources Dome stc installations ; apartment house, office building, school,... | |
| National Center for Air Pollution Control (U.S.) - Air - 1966 - 308 pages
...single source of emission of any air contaminant which is as dark or darker than Rlngelmann No. 2 and of such opacity as to obscure an observer's view to a degree equal to or greater than Ringelmann No. 2 for a. period or periods aggregating more than three minutes in one hour is prohibited.... | |
| Air - 1966 - 692 pages
...sixty minutes air contaminants of a shade or density not darker than No. 2 on the Ringelmann Chart. 2. Of such opacity as to obscure an observer's view to a degree not greater than does smoke described in subsection C (1) of this regulation. 3. Where the presence... | |
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