Strain-Sensing Alloys

The principal component which determines the operating characteristics of a strain gage is the strain-sensitive alloy used in the foil grid. However, the alloy is not in every case an independently selectable parameter. This is because each Micro-Measurements strain gage series (identified by the first two, or three, letters in the alphanumeric gage designation ) is designed as a complete system. That system is comprised of a particular foil and backing combination, and usually incorporates additional gage construction features (such as encapsulation, integral leadwires, or solder dots) specific to the series in question.

Micro-Measurements supplies a variety of strain gage alloys as follows (with their respective letter designations):

A-Alloy Constantan, a nickel-copper alloy, in self-temperature-compensated form .

P- Alloy Annealed constantan.

D-Alloy Isoelastic nickel-chromium alloy.

K-Alloy Nickel-chromium alloy, a modified Karma in self-temperature-compensated form .

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