Dust measuring apparatus

Abstract

Abstract PURPOSE: To measure the amount of dust in air accurately, by determining a ratio of reflection or transmission of a light between a part having dust trapped with a filter for trapping dust and a white part with no dust trapped. CONSTITUTION: An air passage hole 9' is made in an inner lid 7 and a fixed amount of atmospheric air is sucked through the air passage hole 9'. Air sucked is introduced to a pump through a dust trapping filter 4, when dust in the air is trapped to the circumference of the filter except for a lower part of a rubber body 8 for preventing passage of air. Thus, the center of the filter 4 looks white while the circumferential part thereof is colored according to the amount of dust. After the trapping of dust, the lid 7 is removed to let light irradiate a central white part 5 of the filter 4 and the dust attached part in the perimeter thereof. A ratio of transmission light or reflected light between both the parts is determined to measure the amount of dust in the air from the ratio. COPYRIGHT: (C)1989,JPO&Japio

Inventors

• 👤 Kazuo Amaya

Bibliographic Details