LIQUID LEVEL SENSOR

PURPOSE:To provide a liquid level sensor, in which liquid adhesion to a sensor head is prevented so as to eliminate any error action. CONSTITUTION:The level sensor consists of a light transmitting optical fiber 1, a light receiving optical fiber 2, and a sensor head 3 arranged in the end of the optical fiber, and the sensor head 3 made of a transparent fluororesin has a prism-shaped tip part 4 provided with a top angle of 100 deg., while a plate extending downward from the prism top end is provided in the prism-shaped tip part 4 of the sensor head 3 so as to prevent liquid drop adhesion to the outside face of the prism. The sensor head 3 including the prism tip part 4 is integrally molded with a protecting tube 6 made of a fluororesin, and is fixed with the optical fibers 1, 2 by a mouthpiece 7. A tube for preventing falling off and for sealing may be arranged on the inside/outside of the protecting tube 6.