1.1 This standard ( Part III) prescribes two methods for the measurement of the foaming power of a surface active agent. The methods are applicable to all surface active agents. Method A, known as the Ross-Miles method, shall be the referee method and shall be used in case of any dispute. Method B shall be the alternate method.
1.1.1 Measurement of the foaming power of solutions of readily hydrolysable surface active agents by these methods does not give reliable results, as the hydrolysis products collect in the films of liquid and affect the persistence of the foam.
Note — The persistence of liquid films is very sensitive to the presence of particles of insoluble matter. This method of measurement of foaming power should be used only with the greatest of care, for measuring the foaming power of compositions based on surface active agents of which the solubility is rarely complete. Foaming power is also very sensitive to small variations in composition. Consequently, the results obtained on formulated products should be interpreted with caution.
1.1.2 The methods are not applicable for measurement of the foaming power of very dilute solutions of surface active agents, such as river water containing surface active agents.
IS 5785 Pt.3-1970 history
1971IS 5785 Pt.3-1970 Surfactant Performance Test Methods Part III Foaming Capacity