Abstract: A density sensor to measure the density of a gas having a density ranging from 30 gram per cubic meter to 150 kilogram per cubic meter and a working pressure ranging from 0 to 100 bar. The density sensor includes a resonator housing, a membrane, an actuating/detecting module mechanically coupled to the membrane, and a resonating element arranged to be immersed in the gas, the resonating element being mechanically coupled to the membrane by a pedestal. The resonating element is a resonating disk having a thickness ranging from 25 ?m to 200 ?m and a diameter ranging from 4 mm to 12 mm. The resonating disk extends parallelly to the membrane or being angled relatively to the membrane and is coupled by its center to the pedestal. The resonating disk is made of a metal chosen among the group comprising stainless steel, nickel-iron alloy and Molybdenum.

Abstract: A density sensor (1) to measure the density of a gas having a density ranging from 30 gram per cubic meter to 150 kilogram per cubic meter and a working pressure ranging from 0 to 100 bar comprises: a resonator housing (6) defining a chamber (7) isolated from the gas, the resonator housing (6) comprising an area of reduced thickness defining a membrane (4) separating the chamber (7) from the gas; an actuating/detecting module (5) positioned within the chamber (7) so as to be isolated from the gas and mechanically coupled to the membrane (4); and a resonating element (2) arranged to be immersed in the gas, the resonating element (2) being mechanically coupled to the membrane (9) by a pedestal (3). The membrane (4), the pedestal (3) and the resonator housing (6) are made of metal. The membrane (4) has a thickness enabling transfer of mechanical vibration between the actuating/detecting module (5) and the resonating element (2) through the pedestal (3).