| 摘要 |
<p>PURPOSE:To continuously and momently detect the presence or the absence and the depth of liquid in a measurement range with less malfunction by immersing a fluorescent optical fiber in liquid of flow transparency and detecting the quantity of light from the end face in the axial line direction which is changed in accordance with liquid surface. CONSTITUTION:Light to a fluorescent optical fiber 1 where a length l of an outside peripheral part 2 which receives external light 6 and the intensity of emission of light from an end face 3 in the axial line direction unequivocally and continuously correspond to each other is shielded by liquid 4 of low transparency. Consequently, the length l is shortened according as the depth of liquid 4 is increased, and a maximum intensity of emission is reduced when there is no liquid in a storage vessel 5. These relations are preliminarily programmed in a discriminating part 8, and the presence or the absence and the depth of liquid 4 are automatically detected at the time of detecting the intensity of emission by a light receiving part 7. This method can momently and continuously cope with the change of the liquid surface because the luminescence response speed of the fiber 1 is very high, and an electric noise and an electromagnetic field have no influence and the malfunction is difficult to occur.</p> |
