Measuring system for a pressure gauge and method for manufacturing a measuring system for a pressure gauge

The measuring instrument for a pressure gauge comprises an indicator unit (2) with two plates (4, 6) that bear rotatably an indicator shaft (24) carrying a pinion (28) and that furthermore bear a gear segment (32). The measuring instrument furthermore comprises a metal Bourdon tube (48) bent into an arc shape, which is soldered on one end to a spring carrier (40) and on the other to a spring end-piece (54). The spring end-piece (54) is connected to the gear segment (32) such that the displacement of the spring end-piece (54) because of the measurement pressure is transferred to the gear segment (32). The spring end-piece (54) constitutes a part that is rigidly attached to one of the two plates (4, 6) prior to the Bourdon tube (48) being soldered to the spring end-piece (54) and that is separated from this plate once the Bourdon tube (48) has been soldered to the spring end-piece (54). During the course of the manufacture of this measuring instrument, the spring end-piece (54) is produced as a part that is securely joined to the two plates (4, 6). The Bourdon tube (48) is soldered to the spring end-piece (54) while the latter is still rigidly affixed to the plate. It is not until thereafter that the spring end-piece (54) is separated form the plate. Preferably the spring carrier (40) is integral to or attached to one of the two plates (4, 6). The spring end-piece (54) assumes its target position with greater accuracy with respect to the indicator unit (2).