| 摘要 |
PROBLEM TO BE SOLVED: To provide a water level detection device for detecting a water level in a tank, which includes a function capable of diagnosing failure of the water level detection device itself without adding newly another detection device. SOLUTION: A failure diagnosis function of the water level detection device can be achieved with a simple constitution by including: a water tank 7 for storing liquid; a water level sensor 10 constituted by combination of a light emitting element 10a for radiating light and a light receiving element 10b for detecting a light quantity, for detecting existence of water 8 in the water tank 7 from a detection result by the light receiving means 10b; a first optical path part for allowing light radiated from the light emitting element 10a to reach the light receiving element 10b; a second optical path part for allowing a part of the light radiated from the light emitting element 10a to reach the light receiving element 10b; and a determination part 11 for detecting the level of water 8 stored in the water tank 7 based on the light quantity detected by the light receiving element 10b, and detecting failure of the light emitting element 10a or the light receiving element 10b. COPYRIGHT: (C)2011,JPO&INPIT |
