| 摘要 |
<p>To measure the amount of liquid fuel in a ventilated fuel tank (1), the ventilation of the tank is stopped temporarily by a valve (7) and gas is removed from or fed into the unventilated tank through a device (12). A quantity indicative of the change in the gas state in the tank is measured after feeding in or removal of the gas to provide an indirect measurement of the amount of fuel in the tank. The gas may be removed from or fed into the tank at a constant volumetric flow rate, in which case the quantity measured will be the time taken for a predetermined alteration in the pressure of gas in the tank to occur. Alternatively, gas may be removed until a predetermined reduced pressure in the space in the tank is reached and the volume of gas removed can provide a direct or indirect measure of the amount of fuel in the tank. As a second alternative a predetermined volume of gas is removed and the alteration in pressure of the gas in the tank is measured.</p> |
