Abstract: The variometer includes a measuring chamber communicating with the atmosphere through a first passageway and an elastically deformable measuring box, positioned within the measuring chamber, communicating with the atmosphere through a second passageway. One of the passageways, preferably the second passageway, is provided with a system of orifice inserts serving to delay pressure equalization between the measuring chamber and the measuring box. The system of orifice inserts includes at least two orifice inserts with successive orifice inserts being separated from each other by an intermediate space. The orifice inserts are threaded into the internally threaded bore of a hollow screw, and preferably three orifice inserts are provided so as to define two intermediate spaces. At least one of the orifice inserts is displaceable axially of the hollow screw, and preferably two orifice inserts are so displaceable.