Relative Humidity 16 : The amount of water vapor or moisture held in suspension in gas or air, expressed as a percentage of the amount of moisture that would be held in suspension at the same temperature if saturated
Ralph W. Burklin & Robert G. Purington, Fire Terms: A Guide to Their Meaning and Use, National Protection Association, Boston, MA 1980 USA. (Guide: Meaning and Use, Nat Prot Association Fr Srvc - Amer) {457}