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What is a resistance strain gauge
Nov 17, 2017

What is a resistance strain gauge



A resistor strain gage is a component used to measure strain. It can convert the change of strain on the mechanical component to the resistance change. The Resistance strain Gage is made of a two-layer insulating sheet (the substrate) sandwiched between a φ=0.02-0.05mm copper wire or a Shan (or a grid shaped by a thin metal foil). The silver-plated copper wire is connected with the strain gauge wire grid, and is used as a resistor chip lead.


strain gauge.jpgThe measurement principle of the resistance strain Gage is as follows: The resistance value of the wire is related to the length and cross-sectional area of the wire except the property of the material. The metal wire is pasted on the component, and the length and cross-section area of the metal wire change with the component when the component is deformed, and the resistance changes.

dR/R=Ks*ε

Among them, KS is the sensitive coefficient of material, its physical meaning is the resistance change rate of unit strain, which indicates that the resistance strain gage effect of this kind of wire is remarkable or not. ε is the strain at the measuring point, which is dimensionless, but it is still customary to give the unit micro-strain, commonly used symbol με expression.

As a result, the strain ε and the resistance change rate dr/r linearly in the strain effect, which is the theoretical basis of using metal strain gage to measure the strain of the component.