Altitude measurement device including an atmospheric pressure sensor arranged to be compressed or to expand in a rectilinear direction as a function of the atmospheric pressure to be measured which increases or decreases, wherein the movements of deformation of the atmospheric pressure sensor are transformed, via a transmission system, into a pivoting motion, in a plane perpendicular to the rectilinear direction of deformation of the atmospheric pressure sensor, of an activation system which drives the pivoting of an indicator hand, wherein the indicator hand moves over a graduated circular scale, wherein the atmospheric pressure sensor is arranged to be able to be moved in one direction or in the opposite direction depending on the rectilinear direction of deformation thereof relative to the other components of the altitude measurement device, wherein the atmospheric pressure sensor is mounted on a seat which is fixed in a support, which forms a case with a cover.

A remotely interrogatable pressure transition indicator (100) having a pressure sensitive element (110) interacting with a remotely interrogatable mechanical switch (120). The pressure sensitive element (110) is a hermetically sealed, gas impermeable, flexible walled sachet (110) containing a quantity of gas, operable for transitioning between inflated and deflated conditions induced by a change in external gaseous pressure experienced by the sachet (110). The sachet (110) interacts with the mechanical switch (120) to producing a first interrogatable value when the sachet (110) is inflated and a second interrogatable value when the sachet (110) is deflated.