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Turbidity between 1 and 50 recorded to nearest unit 〃 〃 51 〃 100 〃 〃 〃 5 〃 〃 101 〃 500 〃 〃 〃 10 〃 〃 501 〃 1000 〃 〃 〃 50 〃 〃 1001 〃 greater 〃 〃 〃 100

The quotient obtained by dividing the weight of suspended matter in the sample by the turbidity, both expressed in the same unit, shall be called the coefficient of fineness. If the quotient is greater than unity the matter in suspension is coarser and if it is less than unity it is finer than the standard.

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The “color,” or the “true color,” of water shall be considered the color that is due only to substances in solution; that is, it is the color of the water after the suspended matter has been removed. In stating results the word “color” shall mean the “true color” unless otherwise designated.

The “apparent color” shall be considered as including not only the true color but also any color produced by substances in suspension. It is the color of the original unfiltered sample.

The platinum-cobalt method of measuring color shall be considered as the standard, and the unit of color shall be that produced by 1 part per million of platinum.