Liquid supply monitoring apparatus.

摘要

Known means for sensing the imminent depletion of the contents of a liquid fuel tank, for example, a float connected to an electrical transducer do not work well in the zero gravity of space. Following the realisation that when the fuel in a pressurised spacecraft fuel tank is near depletion bubbles of the pressurising gas start to appear in the outlet duct (2) from the tank, there is proposed herein a simple fuel depletion sensor (1) especially for spacecraft comprising a bubble sensor coupled to the outlet duct. The detector can comprise a light source (3) and an opto-electrical transducer (4).