Abstract: A device for measuring gas pressure that is dependent upon the level of a liquid comprises a pressure indicator or sensor (6, 6′) which is connected to an upper part of a tube conduit (7, 7′) which is filled with gas and intended to operate in a liquid mass, said conduit having a lower part connected to an upper part of a vessel (8, 8′) with a volume that is larger than the volume of the tube conduit. The vessel (8, 8′) has an inlet (13) to let the liquid in, which inlet has a cross-sectional area that is smaller than the cross-sectional area of the vessel and that is located near the bottom of the vessel. Therefore, liquid that penetrates into the vessel via the inlet forms a surface whose level in itself in the vessel may vary depending upon the level of the surrounding main liquid mass, however normally without the liquid rising up into the tube conduit (7, 7′) as such.