Ultrasonic fluid gauging system for tank containing e.g. fuel - has transducer disposed at bottom of still well in tank along which multiple reflectors are spaced at heights which are not simple multiples of each other

摘要

The fluid gauging system has several probes disposed in a tank, each probe (2) having an ultrasonic transducer (13) at the bottom of a still well (12) and several reflectors (14-22) spaced along the length of the still well. The transducer (13) transmits acoustic energy along the probe to the fluid surface and receives the energy reflected by the surface and the reflectors. The height of the second reflector (15) above the transducer (13) is less than twice the height of the first reflector (14), and all the reflectors are located at heights that are not simple multiples of the height of any lower reflector, with false echoes being identified from the absence of reflections from reflectors between the actual fluid surface and the false echo.