STANDARD SALT SOLUTIONS FOR HUMIDITY CALIBRATION Saturated aqueous solutions of inorganic salts are convenient secondary standards for calibration of instruments for measure-ment of relative humidity. The International Union of Pure and Applied Chemistry has recommended salt solutions for cali-brations in the range of 10% to 90% relative humidity, and the American Society for Testing and Materials has published similar standards. The data in this table are taken from the IUPAC recom-mendations, except for K 2 CO 3 and K 2 SO 4 , which are ASTM rec-ommendations. Details on the preparation and use of these standards may be found in References 1 and 2. Data for other salts are given in Reference 3. References 1. Marsh, K. N., Editor, Recommended Reference Materials for the Realization of Physicochemical Properties , Blackwell Scientific Publications, Oxford, 1987, pp.157-162. 2. Standard Practice for Maintaining Constant Relative Humidity by Means of Aqueous Solutions , ASTM Standard E 104-85, Reapproved
This is the end of the preview.
access the rest of the document.