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Control of Humidity with Potassium Hydroxide, Sulphuric Acid, or other Solutions

Published online by Cambridge University Press:  10 July 2009

M. E. Solomon
Affiliation:
Department of Scientific & Industrial Research, Pest Infestation Laboratory, Slough, Bucks.

Extract

Methods of preparing solutions of graded density for the accurate control of atmospheric relative humidity are described, and some pitfalls in their use and in the use of saturated salt solutions are indicated.

For graded solutions of potassium hydroxide and of sulphuric acid, data from the International Critical Tables or more recent sources are used as the basis of tables giving the concentrations (wt.%) and densities corresponding to relative humidities in steps of 5 per cent. R.H. Sources of similar data for calcium chloride, sodium hydroxide, sodium chloride, and glycerol solutions are given.

As an addition to the compilation of the available data on humidities in contact with various saturated salt solutions by O'Brien (1948), some more recent figures are quoted.

Type
Original Articles
Copyright
Copyright © Cambridge University Press 1951

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References

Beattie, M. V. F. (1928). Observations of the thermal death points of the blow-fly at different relative humidities.—Bull. ent. Res., 18, pp. 397403.CrossRefGoogle Scholar
British Standards Institution. No. 718. (1936). British Standard Specification for density hydrometers. 52 pp.Google Scholar
British Standards Institution. British Standard density-composition tables for use in conjunction with B.S. density hydrometers :—Google Scholar
British Standards Institution. No. 753. (1937). For aqueous solutions of sulphuric acid, 68 pp.Google Scholar
British Standards Institution. No. 823. (1938). For aqueous solutions of sodium chloride and of calcium chloride, 36 pp.Google Scholar
British Standards Institution. No. 824. (1938). For aqueous solutions of caustic soda, 47 pp.CrossRefGoogle Scholar
Buxton, P. A. (1931). The measurement and control of atmospheric humidity in relation to entomological problems.—Bull. ent. Res., 22, pp. 431447.Google Scholar
Buxton, P. A. & Mellanby, K. (1934). The measurement and control of humidity.—Bull. ent. Res., 25, pp. 171175.CrossRefGoogle Scholar
Carr, D. S. & Harris, B. L. (1949). Solutions for maintaining constant relative humidity.—Industr. Engng Chem., 41, pp. 20142015.CrossRefGoogle Scholar
Collins, E. M. (1933). The partial pressures of water in equilibrium with aqueous solutions of sulfuric acid.—J. phys. Chem., 37, pp. 11911203.Google Scholar
Davis, D. S. (1942). Vapour pressure nomographs for aqueous sodium hydroxide solutions.—Industr. Engng Chem., 34, pp. 11311132.Google Scholar
Grover, D. W. & Nicol, J. M. (1940). The vapor pressure of glycerin solutions at 20°.—J. Soc. chem. Ind., Lond., 59, pp. 175177.Google Scholar
Handbook of Chemistry and Physics.—Ed. Hodgman, C. D.. (Frequent editions.) Cleveland, Ohio, Chem. Rubb. Publ. Co.Google Scholar
Harned, H. S. & Cook, M. A. (1939). The thermodynamics of aqueous sodium chloride solutions from 0 to 40° from electromotive force measurements.—J. Amer. chem. Soc., 61, pp. 495497. (Chem. Abstr., 33, 3663·5.)CrossRefGoogle Scholar
International Critical Tables. Ed.-in-Chief, Washburn, E. W.. Publ. for Nat. Res. Council by McGraw-Hill Co., N.Y. & London, Vol. 3, 1st edn., 1928.Google Scholar
Janis, A. A. & Ferguson, J. B. (1939). Sodium chloride solutions as an isopiestic standard.—Canad. J. Res., (B) 17, pp. 215230. (Chem. Abstr., 33, 8476·6.)Google Scholar
Johnson, C. G. (1940). The maintenance of high atmospheric humidities for entomological work with glycerol-water mixtures.—Ann. appl. Biol., 27, pp. 295299.Google Scholar
Landolt-Börnstein, . Physikalisch-chemische Tabellen. Berlin, J. Springer.Google Scholar
O'Brien, F. E. M. (1948). The control of humidity by saturated salt solutions.—J. sci. Instrum., 25, pp. 7376.Google Scholar
Pickering, (1894). Phil. Mag., 37, p. 359. (Int. crit. Tabl., 3, pp. 86, 110.)Google Scholar
Schoof, H. F. (1941). The effects of various relative humidities on the life processes of the southern cow-pea weevil, Callosobruchus maculatus (Fabr.) at 30°C., ±0·8°.—Ecology, 22, pp. 297305.Google Scholar
Shankman, R. & Gordon, A. R. (1939). The vapour pressure of aqueous solutions of sulphuric acid.—J. Amer. chem. Soc, 61, pp. 23702373.Google Scholar
Shelford, V. E. (1929). Laboratory and field ecology. Baltimore, Williams & Wilkins.Google Scholar
Solomon, M. E. (1937). Experiments on the effects of temperature and humidity on the survival of Halotydeus destructor (Tucker), Acarina fam. Penthaleidae.—Aust. J. exp. Biol. med. Sci., 15, pp. 116.Google Scholar
Solomon, M. E. (1945). The use of cobalt salts as indicators of humidity and moisture.—Ann. appl. Biol., 32, pp. 7585.Google Scholar
Stevens, N. E. (1916). A method for studying the humidity relations of fungi in culture.—Phytopathology, 6, pp. 428432. (From Shelford (1929).)Google Scholar
Stokes, R. H. & Robinson, R. A. (1949). Standard solutions for humidity control at 25°C.—Industr. Engng Chem., 41, p. 2013.Google Scholar