Abstract: A method for determining liquid quantity in a tank holding liquid and a plurality of vapor bubbles in a microgravity environment includes a jet inducer and a sensor for providing a signal proportional to the volume of liquid in the tank. The jet inducer, comprising of a pump and a nozzle, induces a recirculating jet in the tank. The liquid jet merges the plurality of vapor bubbles into a single, nearly spherical vapor bubble and holds the single vapor bubble in a stable location at one end of the container. One or more ultrasonic sensors, at the other end of the tank, measure the distance from the single vapor bubble to the sensor or sensors and generates a signal proportional to the distance measured. A CPU receives and adjusts the signal or signals and generates a readout indicating the volume of the liquid in the container.