SYSTEM AND METHOD FOR SENSING MATERIAL LEVEL WITHIN A CONTAINER

摘要

A system for sensing the surface level (2) of flowable material within a container (4), comprises a drop weight (6) secured to a cable (8) through a pulley (10) for being disposed above the material and brought into contact with the surface level of the material. The cable is wound and anchored to a spool (12) driven by a reversible motor (14). A transducer (16) operably secured to the pulley provides an output responsive to the strain on the cable exerted by the drop weight. A signal processor (18) connected to the transducer generates an output signal responsive to the drop weight being supported by the material. A pulse generator generates a plurality of pulses the number of which is proportional to the amount of rotation of the spool. A programmable controller (28) drives the motor a forward direction to lower the drop weight toward the material surface and in the opposite direction to raise the drop weight substantially the same distance after the processor has detected that the drop weight has landed on the material surface and calculates the surface level of the material based on the number of plurality of pulses generated by the pulse generator during rotation of the spool in the forward and reverse directions. A display (32) is connected to the controller for displaying the calculated level of the material surface. A method for sensing the material level within a container is also disclosed.