Steam wetness measuring apparatus

Abstract

A steam wetness measuring apparatus comprises a light source, a part defining a measuring space when the apparatus is inserted into a wet steam flow, an optical fiber bundle for transmitting the incident light beam from the light source to the measuring space, and optical fiber bundles for transmitting to a photo-electric converter element a plurality of scattered light beams of different scattering angles obtained by radiation of the incident light beam on the measuring space. The fact that the intensity of the scattered light beam changes with the wavelength of the incident light or changes with the scattering angle of the scattered light beam, in accordance with the particle size distribution of water droplets in the wet steam is used to determine the particles size distribution. The steam wetness is determined from the particles size distribution and the physical properties of the wet steam flow.