| 摘要 |
PURPOSE:To minimize a luminous loss at an outgoing end and also to improve a detection sensitivity by providing a taper zone from a curved section to the outgoing end of a U-shaped glass detection rod. CONSTITUTION:LED 3 is kept opposite to one end of a detection rod 1 having a curve through a light introducing handle fiber 2 same diametrically as the end face, and a phototransistor 6 is then kept opposite to the other end through a light introducing handle 5 same diametrically as a taper zone 4 expanding from the curve toward the end face. In a handle level gauge thus constituted, light from LED 3 gets into liquid when the level comes below the detection glass rod, and since the rate of it getting thereinto is proportional to a portion of the glass rod under the level, the level can be measured by allowing a constant rate of the light from LED 3 to be incident and measuring its outgoing rate with the phototransistor 6. The light outgoing from the end face is settled in an opening of the handle fiber 5 by a total reflection at the taper zone 4, thus minimizing a luminous loss. |
