Instrument for indicating the level of low-boiling liquefied gases

The measurement of the level of low-boiling liquefied gases in vacuum-insulated containers is effected by differential manometers which indicate the weight of the liquid column, present in the container, under standard conditions. In practice, this is not always sufficient. At high pressure and a correspondingly high liquid temperature, the density of the liquid decreases, which leads to false measurements. For compensating the temperature influences, a measuring vessel (1), which is connected via a line (8) to a transfer vessel (2), is located in the liquid. The system is filled with a gas which does not condense under the operating conditions of the vessel. This gas acts on a diaphragm (3) which is located in the transfer vessel and on which a pin (7) is fixed which acts on the zero compensation of the differential manometer.