| 摘要 |
PURPOSE: An indoor dust density alarm is provided, which has a high performance with a low price, and makes an alarm if an indoor dust density reaches a health danger value. CONSTITUTION: An aerodynamic dust concentrator part(8) concentrates dust in air to improve scattering of a light. A light emitting part(1) generates a light. A scattering part(2) acts as a dust path in air vertically through a focus of the light generated from the light emitting part collected through a lens. An air absorbing part(9) absorbs air to the dust concentrator and the scattering part. A light receiving part(3) collects light scattered from the scattering part through the lens and then converts it into an electrical signal. A signal processing part(4) converts the electrical signal into a dust density, and judges whether the converted dust density is harmful to human body. And a display part(5) displays the dust density and the harmfulness to human body.
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