DEVICE FOR DETERMINING CONCENTRATION OF AEROSOL IN GASES Russian patent published in 1997 - IPC

FIELD: check of dust content in atmosphere and gas flows. SUBSTANCE: device has source of constant voltage, sensitive and reference elements which operation is based on effect of surface acoustic waves. Each element is composed of piezosubstrate with section for precipitation of aerosol particles and interdigital converters positioned on it and having two bonding pads as well as autogenerating amplifiers and mixer. Each amplifier is connected with its input to bonding pads of converters of corresponding sensitive and reference elements and with output, to input of mixer and other bonding pads of converters. Reflectors of resonator of surface acoustic waves manufactured in the form of periodic grids of strips are located on both sides of converters so hat strips of each reflector and converter nearest to it form unified grid with one spatial period. Distance between grids of strips is equal to their period, strips of both reflectors are electrically intercoupled by buses on both ends and are connected to strips of converters through one of bonding pads of each converter. Autogenerating amplifiers are placed between bonding pads of converters connected to buses which connected to source of constant voltage through time relay. EFFECT: increased operational sensitivity. 1 dwg