Pressure Instruments – Bourdon Tubes

A Bourdon tube (Figure 400-3) is a curved metal tube closed at one end and fixed to a pressure source at the other. Application of pressure at the fixed end results in movement at the free end as the tube cross section deforms. Bourdon tubes come in a C shape, spiral, or helix, depending on the pressure to be measured. The Bourdon tube is the most commonly used element for pressure gages.

Three Types of Bourdon Tubes