what is the difference between Diaphragm and Bellow type differential Pressure gauges?

Answer 1

#In gauges intended to sense small pressures or pressure differences, or require that an absolute pressure be measured, the gear train and needle may be driven by an enclosed and sealed bellows chamber, called an aneroid, which means "without liquid". (Early barometers used a column of liquid such as water or the liquid metal mercury suspended by a vacuum.) This bellows configuration is used in aneroid barometers (barometers with an indicating needle and dial card), altimeters, altitude recording barographs, and the altitude telemetry instruments used in weather balloon radiosondes. These devices use the sealed chamber as a reference pressure and are driven by the external pressure. Other sensitive aircraft instruments such as air speed indicators and rate of climb indicators (variometers) have connections both to the internal part of the aneroid chamber and to an external enclosing chamber.

#The Diaphragm Pressure Gage uses the elastic deformation of a diaphragm (i.e. membrane) instead of a liquid level to measure the difference between an unknown pressure and a reference pressure.

A typical Diaphragm pressure gage contains a capsule divided by a diaphragm, One side of the diaphragm is open to the external targeted pressure, PExt, and the other side is connected to a known pressure, PRef,. The pressure difference, PExt - PRef, mechanically deflects the diaphragm.
*Pros:
- Much faster frequency response than U tubes.
- Accuracy up to ±0.5% of full scale.
- Good linearity when the deflection is no larger than the order of the diaphragm thickness.

Answer 2

The diaphram type uses small deflections of a thin membrane (the diaphragm) to convert pressure differences into mechanical motion proportional to the pressure differential. The bellows type has a bellows (which looks a bit like an acordian) capsule to do the same job. The bellows type is usually more sensitive than the diaphragm type, but the diaphram types can handle quite a bit more pressure.

Doug

Answer 3

The 12 gauge has a nominal bore diameter of .729 inch. For over 100 years the 12 gauge has been the all-around choice of North American and British shotgunners. It is the only choice for Trap or live pigeon shooting, the most common choice for Sporting Clays and Skeet, and the overwhelming choice for waterfowl shooting. Many upland game hunters also favor a lightweight 12 gauge shotgun, although as an upland gun it has gotten lots of competition over the years from the 16 and 20 gauges. The 20-gauge shotgun is a type of shotgun that is less common than the 12-gauge. This may be because the 20-gauge shotgun has a smaller diameter (caliber) bore than the 12-gauge. Specifically, it takes 20 balls of the diameter of a 20-gauge shotgun bore to equal 1 pound, while it only takes 12 balls of the diameter of a 12-gauge shotgun bore to equal the same amount. A 20-gauge shotgun is sometimes considered more suitable for hunting certain types of game, because it destroys less of a game animal's meat. Certain sizes are more common than others; 12-gauge is the most common size, with up to 50% of the overall shotgun market in the United States. The 20-gauge shotgun is popular with shooters who are uncomfortable with the weight and recoil of a 12 gauge gun, and is popular for upland game hunting