Abstract: A device which is used to measure the density of a liquid, includes an enclosure (1) which is impervious to the liquid to be measured. The enclosure (1) has a rigid deformation-resistant casing housing at least one reference body (3) which is suspended in the enclosure (1). The enclosure (1) can move in relation to the reference body (3) such as, in the fully submerged state, to occupy a position which is a function of the density of the liquid in which the device is submerged. In the position, the enclosure exerts a pressure or tensile force on a measuring device (2) the movement of which is limited by the reference body (3).