| 摘要 |
PURPOSE:To enable detection of a snowfall discriminately from a rainfall and to release automatically the detection signal when the snowfall ends by measuring the presence or absence of the snow laid on an inclined reflecting plate as a change in the quantity of light and removing the laid snow at a fixed cycle. CONSTITUTION:A reflecting plate 10 is installed obliquely so as to face a light emitting part 3. A photodetecting part 4 receives the light reflected from the reflecting plate and detects the decrease in the quantity of the reflected light from the snow deposited on the reflecting plate. A control parts 2 starts snow- removing mechanisms 12, 13 of the plate 10 and a light emitting and receiving part 1 at every set time. The device is provided with an electric power source for the control part and a transmitter 16 of a detection signal. |
