How does a strain gauge work?
Strain Gauge Basics A strain gauge is a device used to measure the mechanical strain on an object or structure. When an object is under a lot of pressure, the material can slowly fatigue and begin to subtly bend. These bends, nearly impossible to see with the naked eye, can be early indicators that a building is aging or beginning to buckle. Strain gauges constantly measure these minute changes, giving engineers an easy way to monitor a structure’s condition. Strain Gauge Structure A strain gauge usually consists of a long strip of metal foil attached to a sheet of flexible material.The strip is thin and long, and zig-zags back and forth between the insulating sheets to maximize its length. At each end, the gauge is attached to a Wheatstone bridge, a device that measures its resistance. The gauge is cemented onto whatever surface it is meant to measure. How It Works The metal foil is a resistor—it conducts electricity but also resists its flow somewhat. When the sheet is bent one way
