OPTICAL DUST METER IN SYSTEM FOR CONTROLLING VENTILATION OF INDUSTRIAL ROOMS Russian patent published in 2003 - IPC

FIELD: systems for measuring dust concentration in rooms of industrial plants in order to control ventilation equipment according to dust concentration value. SUBSTANCE: dust meter includes light source energized by pulse voltage power source connected in series and optically coupled with inlet of light beam splitter; apparatus for monitoring dust content of protective window; temperature monitoring unit and apparatus for heating up inspection windows. First outlet of light beam splitter is connected in series and optically coupled with first protective window, with measuring circuit, with second protective window and with first inlet of unit for processing signals. Second outlet of light beam splitter is connected in series and optically coupled with reference duct filled with dust-free gas mixture whose content is similar to that of exhaust gases of industrial plant, with second inlet of unit for processing signals. Apparatus for monitoring dust content of protective window is optically coupled with protective window in measuring circuit whose outlet is used as inlet of control device. Outlet of the last is connected with apparatus for blowing off inspection windows. Outlet of temperature monitoring unit is connected with inlet of unit for processing signals. Apparatus for heating up inspection windows is connected with heating members arranged in protective windows. EFFECT: enhanced accuracy of dust concentration value continuously measured in automatic mode. 4 dwg