POINT MEASUREMENTS OF NONCONDENSABLE GAS CONCENTRATION IN CONDENSING SYSTEMS

Condensation in the presence of noncondensable gases continues to rece ive considerable attention, most recently in the application to contai nment performance for advanced passive nuclear reactors. lit experimen ts, it is often desired to make point measurements of noncondensable g as concentrations under conditions where the,aas concentration can be small and superheat can be significant. This paper presents test resul ts for a novel miniature psychrometer. The tests and analysis presente d here show that a wetted cylindrical body will approach closely the l ocal saturation temperature of an air-steam mixture, under a wide rang e of flow velocities and superheat levels, even when the bulb is allow ed to drip water. This permits local gas concentrations to he measured with high accuracy, particularly when the thermopile method introduce d here is used to measure the wet-bulb temperature relative to a refer ence pure steam temperature generated in a small boiler.