An electrical solution-mixing device

An electrical solution-mixing device

NOTES FROM THE RESEARCH LABORATORY, EASTMAN KODAK COMPANY.* AN ELECTRICAL SOLUTION-MIXING DEVICE: By K. C. D. Hickman and D. Hyndman. ELECTRICAL titr...

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NOTES FROM THE RESEARCH LABORATORY, EASTMAN KODAK COMPANY.* AN ELECTRICAL SOLUTION-MIXING DEVICE: By K. C. D. Hickman and D. Hyndman.

ELECTRICAL titration methods in general use employ electrodes immersed in the reacting liquids and give indications of hydrogen or other ion concentrations. T h e indications have been used by various workers to control automatically the mixing of the two reagents. Such electrical controls m a y be described as operating internally. The present m e t h o d uses externally gaseous indicators such as sulfur dioxide or ammonia, which it detects by an 'electric nose' placed over the reacting vessel. T h e variations in current actuate a valve which limits the particular solution in excess at t h a t moment. In this connection a special mechanism has been devised which requires so little energy for actuation that no amplification or relays are required on the electrical circuit for the 'nose' even t h o u g h thousands of gallons of solution be handled each hour. T h e device is useful both in acidimetry and in oxidation--reduction reactions, particularly with complex mixtures, since only the chosen volatile constituent can affect the control. VECTORIAL TREATMENT OF REFRACTION OF S K E W RAYS BY A PRISM. 2 By L. Silberstein.

TttE incident ray, of a n y orientation, being represented by the unit vector r, the refracted and ultimately emergent ray is expressed by the vector formula, r' = r q- gin1 q- g~.n2 * Communicated by the Director. ~Communication No. 321 from the Kodak Research Laboratories and published in Ind. Eng. Chem. 20: 2I 3. I928. Communication No. 333 from the Kodak Research Laboratories and published in J. Opt. Soc. Amer. I6: 88. 1928. 721