Definition A Bourdon gauge is a pressure measuring device. It is a part of a special class of gauges known as Aneroid Gauges ( Aneroid means without fluid ). They are often called Mechanical Gauges in modern language.
History The Bourdon gauge was invented in 1894 by Eugne Bourdon (18081884) He was a watchmaker and engineer by profession . The gauge created by him could measure pressures up to 100,000 pounds per square inch (690 MPa or 6800 atm), something that had previously been impossible.
ComponentsStationary parts: A: Receiver block B: Chassis Plate C: Secondary Chassis Plate D: Posts to join and space the two chassis plates.
Moving Parts:1. 2. 3. 4. 5. 6. 7. 8. 9. Stationary end of Bourdon tube.* Moving end of Bourdon tube. This end is sealed. Pivot and pivot pin. Link joining pivot pin to lever (5) with pins to allow joint rotation. Lever. This an extension of the sector gear (7). Sector gear axle pin. Sector gear. Indicator needle axle. * Hair spring to preload the gear train to eliminate gear lash and hysteresis.
WorkingWithin the Bourdon gauge is a thinwalled metal tube, somewhat flattened and bent into the form of a C. Attached to its free end is a lever system that magnifies any motion of the free end of the tube. On the fixed end of the gauge is a fitting you thread into a boiler system. As pressure incre ases within the boiler, it travels through the tube and the tube begins to straighten. As the tube
straightens, the pointer moves aro und a dial that indicates the pressure in psi.
How Is It Different From Other Pressure Measuring Devices? It works on the same principle as that of the snakelike, paper party whistle you get at a New Ye ar party, which straightens when you blow into it. The pressure indicated is the difference between that communicated by the system to the tube and the external(ambient) pressure, and this is usually referred to as the gauge pressure. It is then necessary to add on the ambient pressure in order to obtain the (absolute) pressure.
Materials Used for Making A Bourdon Gauge Should have elasticity and flexibility Corrosive resistance Lightweight Cost Factor Examples Phosphor bronze, Stainless Steel, Beryllium Copper
Merits Highly accurate Highly sensitivity Suitable for very high pressures
Demerits Very delicate instrument Malfunctions easily if pressure varies rapidly
Uses Bourdon gauges are often fitted to cylinders of compressed gas used in industry and hospitals. This gauge is widely used for steam and compressed gases, and frequently forms the indicating element on flow controllers
Manufacturers of Bourdon Gauges in India Alot Hitek Pvt. Ltd Japsin Instrumention A L M Engineering & Instrumentation Pvt. Ltd. Waree Instruments Ltd. Wika Instruments India Pvt. Ltd. Manometer (India) Pvt Ltd Precision Industries