THE USE OF RADIOACTIVE ISOTOPES FOR THE MEASUREMENT OF THE MOISTURE CONTENT OF STEAM

A method for continuously measuring the moisture content of steam was tested. The possibility of measuring the average moisture content without sampling and independent of droplet size in the stream was demonstrated. The relative change in intensity of a beam of beta particles from a S/sup 35/ source passing through the stream was used to determine the density of the stream. Moisture content was then obtained by comparing the measured density with tabulated values of density of saturated dry steam. Measurements were taken at a steam velocity of l50m/sec. Description and drawings of the apparatus are included. The apparatus allows measurement of density with steam velocities from 5 to 200 m/sec, moisture content from 0 to 15%, temperature variations from 70 to 180 tained C, and pressure variations from 1 to 0.1 atmospheres. Also the mass absorption coefficient of beta particles was determined from measurements of the relative beam intensity versus thickness of the absorbing steam; in superheated steam the value is 197 cm/sup 2//g. (TTT)