Related Resources : Ringelmann Scale
There is no definitive chart, rather, Prof. Ringelmann provides a specification; where smoke
The data obtained has definite limitations. The apparent darkness of a smoke depends upon the concentration of the particulate matter in the effluent, the size of the particulate, the depth of the smoke column being viewed, and natural lighting conditions such as the direction of the sun relative to the observer while the accuracy of the chart itself depends on the whiteness of the paper and blackness of the ink used.
In use, the observer views the plume at the point of greatest opacity and determines the corresponding Ringelmann Number. A Ringlemann 0, 1, 2, 3, 4 and 5 are equivalent to an opacity of 0, 20, 40, 60, 80 and 100.
5 Related Topics about Ringelmann scaleBritish Standard .. La Station d'Essais de Machines .. Maximilien Ringelmann .. Scale .. Smoke ..