Fluid level sensor

摘要

A fluid level sensor for monitoring a minimum level consists of a transmission light waveguide (1) which ends at the level of the liquid level to be monitored and a reception light waveguide (3) which begins there and between whose endfaces (5, 6) which extend preferably obliquely to the respective longitudinal axes there is a gap (a) which is accessible for the fluid (7). In this way, it is ensured that the optoelectric transducer (4) which is coupled to the reception light waveguide (3) supplies a signal whenever the fluid level is above the minimum level. This reversal of the previously customary principle of signal emission prevents a defect in the monitoring circuit being incorrectly interpreted as a satisfactory level. <IMAGE>