While the wheel of innovation turns faster and faster in the process industry, a more than 160-year-old technology is still used for pressure measurement today. The "Bourdon tube" developed by Eugène Bourdon in 1849 and named after him is still the most common method for mechanical pressure measurement in the gas and oil industry today.

Eugène Bourdon (1808 - 1884)

Baumer Bourdon Haenni is now the competence center for mechanical measuring instruments within the Baumer Group. The principle of the Bourdon tube merges with the Baumer innovation know-how to create latest generation mechanical pressure gauges. For many years, Baumer has reliably been providing them to the petrochemical industry, power stations, water treatment plants, aviation and marine applications, and the food industry.

Picture 2. The patented Bourdon tube of 1848 belongs to the French National Archive in Paris

These Bourdon-tube pressure gauges are easy to handle and maintain. In addition, they are capable of a wide pressure range and offer a high level of accuracy (up to 0.1 % of the end value). Since they do not require an external power source, they are not prone to voltage fluctuations or power outages.

An example from the childhood days of mechanical pressure measurement: The Bourdon spring is clearly visible.

Bourdon tubes, which have different dimensions depending on the nominal sizes of the measuring device and the measuring range, are manufactured from long stainless steel tubes in a bending machine. The Bourdon tubes are given their typical C shape and a flattened cross section. The Bourdon tubes are welded to the connection piece of the measuring device at one end and to the tube end piece at the other end. The welded measuring systems are checked for leaks and undergo an overpressure cycle to eliminate tensions in the material. Then they are welded to the pressure gauge housing in an automated laser welding plant.

The Bourdon tubes are checked for leaks and undergo an overpressure cycle to eliminate

After assembly of the pointer mechanism,the pressure gauge is adjusted and checked upon compliance with measuring range and accuracy class. This is done in a patented, semi-automatic process which virtually eliminates adjustment errors. The pressure gauge is completely assembled, sealed, and packed for shipment.

Most varied pressure gauges by Baumer utilize the Bourdon Tube