| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a dust detector by which the deposit of dust particles inside an installation in which an electric apparatus or the like is installed so as to be closed is detected accurately from the outside and by which the maintenance of the installation is made easy. SOLUTION: A light-emitting-side photoelectric switch 1 and a light-receiving- side photoelectric switch 2 are installed so as to be faced at a prescribed interval. Light-transmitting plates 5, 6 on which dust particles can be deposited are installed between both photoelectric switches 1, 2. When light L which is radiated from the light-emitting-side photoelectric switch 1 is transmitted through the light-transmitting plates 5, 6, a quantity of light which is incident on the light-receiving-side photoelectric switch 2 is lowered according to the deposition amount of the dust particles on the light-transmitting plates 5, 6. When the quantity of light is lowered down to a prescribed set-value level, the photoelectric switch 2 transmits a report signal.</p> |
