A method for at least providing at least a first and a second assembly for manufacturing, respectively, a first reference pressure chamber (1A) which in use in a pressure control device encloses a gas such that the gas is held under a first reference pressure, and a second reference pressure chamber (1B) which in use in a pressure control device encloses a gas such that the gas is held under a second reference pressure, wherein the first reference pressure differs from the second reference pressure, and wherein the pressure control device is suitable for feeding through, on the basis of the reference pressure, a fluid from a first space (I) in which a relatively high pressure prevails to a second space (II) in which a relatively low pressure prevails, the method comprising providing the first and the second assembly such that each assembly for forming the respective reference pressure chamber comprises a casing (3A, 3B) and a plunger part (11A, 11B), while the casing is closed at a first end and the plunger part can at least partly connect with the casing in or adjacent a second end of the casing and is then movable relative to the casing.