The vessel with the pressure to be measured is connected to Bourdon tube 1. End a of spiral tube 1 is sealed shut and is linked by member 2 to lever 3. Member 2 is connected by turning pairs D and C to tube 1 an to lever 3, which turns about fixed axis A and has segment gear b. Segment gear b of lever 3 meshes with pinion 4 which turns about fixed axis B and is rigidly attached to hand 5. When the pressure is increased, tube 1 tends to straighten out, its sealed end a moves to the right, member 2 turns lever 3 with segment gear b which turns pinion 4 and hand 5 along scale d.
$4079$EHP,M$