Bourdonbuizen

Bourdonbuizen are curved tubes, typically C-shaped or helical, used in mechanical pressure gauges. Invented by Eugène Bourdon in 1849, these tubes are flattened and elliptical in cross-section. When a fluid under pressure enters the curved tube, it tends to straighten out. This straightening motion is proportional to the applied pressure.

The free end of the Bourdon tube is sealed, while the other end is connected to the pressure source. As the pressure changes, the sealed end moves. This movement is then mechanically amplified by a system of levers and gears. This amplified motion is used to drive a pointer across a calibrated scale, indicating the measured pressure.

Bourdon tubes are widely used due to their simplicity, robustness, and relatively low cost. They can measure a broad range of pressures, from vacuum to very high pressures, and are suitable for various fluids and gases. However, their accuracy can be affected by temperature fluctuations, vibrations, and mechanical wear over time. Different materials are used for the Bourdon tube depending on the application, such as brass for lower pressures, stainless steel for corrosive environments, and special alloys for extreme temperatures or pressures. Despite the advent of electronic pressure sensors, Bourdon gauges remain a common and reliable choice for many industrial and domestic applications.