Patent ID: 6498641
Filing Date: 2002-12-24
Classification: G01N,Y10S

Abstract:
A method of using a condensation nucleus counter to detect a presence of small-diameter particles entrained in a sample fluid, comprising:introducing the sample fluid flowing at a sample fluid velocity through a sample inlet into an annular pool that is in vapor communication with a working fluid region containing a working fluid, the sample inlet emitting the sample fluid to flow at a flow velocity outwardly in multiple directions across a working fluid surface of the annular pool, the outward flow of the sample fluid expanding across the working fluid surface and thereby decreasing the flow velocity below the sample fluid velocity, the decrease in flow velocity resulting in an increase in diffusion time of working fluid vapor into the sample fluid to form a saturated fluid mixture; directing the saturated fluid mixture from the annular pool to a condensation region having opposing inner surfaces dimensionally configured to increase the saturated fluid mixture flow to a condensation fluid flow rate; cooling the saturated fluid mixture flowing through the condensation region to a supersaturated state that is sufficiently large to cause condensation of the working fluid vapor onto the small-diameter particles entrained in the sample fluid to enlarge their sizes; and directing to a particle detector the small diameter particles whose sizes are enlarged by the condensed working fluid vapor to detect the presence of the small-diameter particles entrained in the sample fluid.