摘要 |
A level sensing apparatus for sensing the level of a fluid in a container is disclosed. The apparatus has a plurality of spaced sensors (15) within a housing (10) locatable in the container. The sensors (15) are separated from the fluid by the housing (10) and each include a high gain amplifier (Q1, Q2) bias components (R, R1, R2) providing a predetermined output intermediate the potential difference across the amplifier when the sensors are in the fluid and a lower output when the presence of gas is detected. |