Pressure guage is first to come to mind.
It causes the Bourdon tube to straighten.
An elastic transducer, that is bourdon tube which is fixed and open at one end to receive the pressure which is to be measured. The other end of the bourdon tube is free and closed. The cross-section of the bourdon tube is eliptical. The bourdon tube is in a bent form to look like a circular arc. To the free end of the bourdon tube is attached an adjustable link, which is inturn connected to a sector and pinion as shown in diagram. To the shaft of the pinion is connected a pointer which sweeps over a pressure calibrated scale.
A bourdon tube is a type of curved tube where the inside radius is smaller than the outside radius. As Force = Pressure x Area this means that when a pressure is applied internally to the tube the greater surface area on the outside causes the tube to straighten out. This is connected via a mechanical linkage to dial on the front of the gauge. Your typical industrial pressure gauge is the Bourdon Tube tyep.
A Bourdon Tube or a Bellows gauge
It is because air can still go into the metal tube, and the atmospheric pressure (14.7 psia) will still force the tube to uncoil a bit. But the reading won't be very high.
It causes the Bourdon tube to straighten.
Eugene Bourdon invented and patented the Bourdon tube pressure gauge.
An elastic transducer, that is bourdon tube which is fixed and open at one end to receive the pressure which is to be measured. The other end of the bourdon tube is free and closed. The cross-section of the bourdon tube is eliptical. The bourdon tube is in a bent form to look like a circular arc. To the free end of the bourdon tube is attached an adjustable link, which is inturn connected to a sector and pinion as shown in diagram. To the shaft of the pinion is connected a pointer which sweeps over a pressure calibrated scale.
Eugene Bourdon 1849 France measures the preasure of liquids and gasses
Bourdon's tube pressure gauge cannot be used to measure negative pressure. This is because absolute pressure must be measured and the Bourdon gauge only indicates the gauge pressure.
The bourdon tube is a curved oval cross-sectional tube. The tendency of a fluid under pressure to try to shape its container, the tube, into a spherical shape causes the tube to elongate, moving the dial mechanism to a position indicating the application of pressure. The greater the pressure applied the greater the movement of the tube.
In 1849, the Bourdon tube pressure gauge was patented in France by Eugene Bourdon.
Bourdon gauge is a type of aneroid pressure gauge consisting of a flattened curved tube attached to a pointer that moves around a dial. As the pressure in the tube increases, the tube tends to straighten and the pointer indicates the applied pressure.
A bourdon tube is a type of curved tube where the inside radius is smaller than the outside radius. As Force = Pressure x Area this means that when a pressure is applied internally to the tube the greater surface area on the outside causes the tube to straighten out. This is connected via a mechanical linkage to dial on the front of the gauge. Your typical industrial pressure gauge is the Bourdon Tube tyep.
------------>[bourdon tube]--------->[level & gear]---------->[pointer,scales]-------> pressure small amplified pressure displacement displacement
The Bourdon pressure gauge uses the principle that a flattened tube tends to change to be straightened or larger circular cross-section when pressurized. Although this change in cross-section may be hardly noticeable, and thus involving moderate stresses within the elastic range of easily workable materials, the strain of the material of the tube is magnified by forming the tube into a C shape or even a helix, such that the entire tube tends to straighten out or uncoil, elastically, as it is pressurized.
It is the gearing, becasue the gears amplify the movement of the bourdon tube into a much larger movement of the needle on the dial. the gears are a mechanical amplifier.