| 摘要 |
PURPOSE:To detect the liquid level with high precision by an optical means using a prism. CONSTITUTION:An optical prism 12, which extends in the vertical direction to the liquid level, is used, and on the optical prism 12, detecting light is projected from a light emitting diode 13a, so that the detecting light is bent and diffused from the prism 12 to the inside of the liquid when a liquid level L exceeds a predetermined position, while the detecting light is reflected inside the prism 12 to be received by the light receiving element 13b when the liquid level L is the predetermined position or below, and the liquid is freely dropped on the surface of the prism 12. |
