| 摘要 |
A fuel gauging system has 3 tanks 21L, 21C, and 21R each containing 14 capacitive probes and a dielectric compensator. Multiplexers 44 and 60 select a single probe or compensator, and an excitation signal from generator 26 is passed therethrough. An empty reference channel 34 is adjusted to pass a signal which compensates for the dry capacitance component of the selected sensor, and a full reference channel 36 likewise for the fully wetted capacitance component. The output of MUX 60 is passed through quadrature filter 66 to a null detector 71. A microcomputer 25 adjusts the channel 36 to balance the partially wetted probe length, and thus determines the wetted length. The fuel volume in a notional section of tank for the sensor is then calculated, according to one of a set of characterization tables selected according to total fuel volume, aircraft in the air or on the ground, etc. The fuel volume for all sensors are added to obtain the total volume in the tank. |
