strain gauge

Device for measuring the changes in distances between points in solid bodies that occur when the body is deformed. Strain gauges are used either to obtain information from which stresses in bodies can be calculated or to act as indicating elements on devices for measuring such quantities as force, pressure, and acceleration.

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Instrument for measuring the condition of a fluid (liquid or gas) that is specified by the force the fluid would apply, when at rest, to a unit area, such as pounds per square inch (psi) or pascals (Pa). The reading on the gauge, called the gauge pressure, is always the difference between two pressures. When the lower of the pressures is that of the atmosphere, the total (or absolute) pressure is the sum of the gauge and atmospheric pressures.

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In manufacturing and engineering, a device used to determine whether a dimension is larger or smaller than a reference standard. A snap gauge, for example, is formed like the letter C, with outer “go” and inner “not go” jaws, and is used to check diameters, lengths, and thicknesses. Screw-thread pitch gauges have triangular serrations spaced to correspond with various pitches, or numbers of threads per inch or per centimeter. Deviation-type or dial gauges indicate the amount by which an object deviates from the standard.

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Gauge may refer to:

In measurements:

• American wire gauge, a measurement of diameter of a wire
• Gauge (bore diameter), the diameter of a shotgun barrel
• Stubs Iron Wire Gauge, which corresponds to the diameter of a hypodermic needle
• See also Wire gauges
• Sheet metal gauge, thickness of metal in sheet form - varies by composition
• Gauge (engineering), any of a variety of measuring instrument
• Sight glass for measuring liquid level heights in storage tanks and pressure vessels
• Gauge blocks, precision measuring standards (Johansson or slip gauges)
• Boost gauge, a gauge used in conjunction with turbo- super-chargers
• Pressure gauge or vacuum gauge, see pressure measurement
• Stream gauge for measuring height and discharge of a river or stream
• The size of a stretched piercing, see stretching (body piercing)
• Film gauge, a physical property of film stock which defines its size
• For gauges on a car dashboard, see Instrument panel
• ANOVA Gauge R&R, a statistical tool to measure variation arising from the measurement device and its operators

In mathematics and physics:

• Gauge (mathematics), a seminorm, a concept related to convex sets
• Gauge theory
• Gauge fixing

In railroads:

• Rail gauge, the distance between the two rails forming a railroad track
• Standard gauge
• Narrow gauge railway
• Broad gauge
• Loading gauge - maximum width and height of engines and loaded wagons, etc.
• Structure gauge - minimum size of bridges, tunnels, platforms, etc.
• Axle load - maximum weight of axles for a given track
• Break of gauge

Other:

• Gauge (knitting), the number of stitches in a given length
• Change of gauge (aviation), when an aircraft type changes at a stopping point of a direct flight
• Gauge (porn star), the stage name of a pornographic film star
• Gauge, post hardcore band from Chicago, IL.
• 12 Gauge, a Canadian country music group, see Emerson Drive

See also

• Gage