| C-type bourdon C-type bourdon tubes are used for ranges as low as 0 — 15 psig and as high as 0 — 1500 psig Helical bourdon Helical bourdon tubes are used for ranges as low as 0 — 200 psig up to 0 — 6000 psig Spiral bourdon Very sensitive units are manufactured to measure as low as 0 -10 psig | The linkage is connected to a pointer or other output device , the tube returns to its original form when the pressure is released |
|---|---|
| The closed end of the bourdon tube is attached to a mechanical linkage | As pressure is applied internally through the open end, the increased pressure causes the flattened cross section to become more circulars and the shape to straighten |
Diaphragms: They consist of a thin layer or disk of a material supported on a rigid frame.
25| Deflection is proportional to the pressure | Absolute pressure ranges as low as 0 -100 mm Hg and gauge pressure ranges as low as 0 -5 inches H 2 O 0 -125 mm H 2 0 are available |
|---|---|
| Due to their robust construction, bourdon are often used in harsh environments and high pressures, but can also be used for very low pressures; the response time however, is slower than the bellows or diaphragm | Bourdon Tubes: It works on a simple principle that a bent tube will change its shape when exposed to variations of internal and external pressure |
There are three common types of bourdon tubes, the C-shape, the spiral, and the helix.