| 摘要 |
PURPOSE:To detect a liquid level with high reliability and high accuracy by adding an optical combining system to a cylindrical liquid level detecting tube having lens action to connect the upper and lower opening space. CONSTITUTION:A cylindrical liquid level detecting tube 10 having the lens action connecting the upper and lower openings 1a, 1b of a container 1, an infrared light emitting diode 11 opposingly installed by pinching the detecting tube 10 and an infrared ray photo-detecting diode 12, etc. are provided. These diodes 11 and 12 are connected in parallel with each other by connecting a current control resistances 13 and 14 in series and one end thereof is connected to the electric power source terminal and the other end to earth. Irradiating the infrared ray emitted from the diode 11 on the diode 12 via the curving face of the detecting tube 10, the current varying with the liquid level is passed to the diode 12, and detecting this current varying state by the voltage comparator 19 of one part of the components of the optical combining system, a detection buzzer 7 and solidstate relay 9 are driven. |
