(A) For the purpose of determining the density of equivalent opacity of smoke, the Ringlemann Chart, as adopted and published by the United States Department of Interior, Bureau of Mines Information Circular 8333, May 1967, shall be used. The Ringlemann number referred to in this section refers to the number of the area of the Ringlemann Chart that coincides most nearly with the visual density of equivalent opacity of the emission of smoke observed. For example, a reading of Ringlemann No. 1 indicates a 20% density of the smoke observed.
(B) All measurements shall be taken at the point of emission of the smoke.
(C) Only in the Light Industrial District shall any business or industrial use emit from a vent, stack, chimney, or combustion process any smoke that is visible to the naked eye. In that district, no use may emit from a vent, stack, chimney, or combustion process any smoke that exceeds a density or equivalent capacity of Ringlemann No. 1 except that an emission that does not exceed a density or equivalent capacity of Ringlemann No. 2 is permissible for a duration of not more than four minutes during any eight-hour period.
(Ord. passed 12-20-2001) Penalty, see § 152.999