| 摘要 |
PURPOSE:To increase sufficiently the quantity of light indicating the height of a liquid level on a display part, and to make the display easy to see and make a precision observation with the naked eye of an operator by allowing LEDs of the display part to illuminate in response to color light from a light emission part and displaying the height of the liquid level. CONSTITUTION:Respective light emission units 2a in the ligth emission part 2 emit green light below the water level and red light above the water level according to the water level in a boiler drum 1. The green or red light of each unit 2a is guided by a fiber 3 and received and converted into an electric signal by a corresponding photodetecting element 4a in a photoelectric conversion part 4. Electric signals as photodetection outputs of respective elements 4a are inputted to respective driving circuits 6a in a driving part 6 and LEDs 5a in the display part 5 are driven with outputs of corresponding circuits 6a to illuminate. In this case, when the elements 4a of the conversion part 4 are sensitive to green light, elements 5a corresponding to units 2a which emit green light illuminates and other elements 5a do not illuminate. Then, the boundary between the illuminating elements 6a and other elements indicates the water level. |
