How does an electrical resistance strain gauge work?
Strain gauges work by measuring the change in electrical resistance across a thin conductive foil. The gauge factor (or “gage factor”) is the sensitivity of the strain gauge (usually 2). It converts the change in resistance to the change in length.
What is an electrical resistive strain gauge?
The electrical resistance strain gauge is a resistance element which changes resistance when subject to strain. However, it will also change resistance when subject to a temperature change. Thus, in order to use it to determine strain, compensation has to be made for temperature effects.
How does a strain gauge function?
Strain gauges convert the applied force, pressure, torque, ect., into an electrical signal which can be measured. Force causes strain, which is then measured with the strain gauge by way of a change in electrical resistance.
How do you measure strain with strain gauge?
Therefore, to measure the strain, you have to accurately measure very small changes in resistance. For example, suppose a test specimen undergoes a strain of 500 me. A strain gage with a GF of 2 exhibits a change in electrical resistance of only 2 (500 x 10-6) = 0.1%. For a 120 Ω gage, this is a change of only 0.12 Ω.
How does a strain gauge load cell work?
Strain gauge load cells usually feature four strain gauges in a Wheatstone bridge configuration, which is an electrical circuit that balances two legs of a bridge circuit. The force being measured deforms the strain gauge in this type of load cell, and the deformation is measured as change in electrical signal.
What is strain gauge factor?
Gauge factor (GF) or strain factor of a strain gauge is the ratio of relative change in electrical resistance R, to the mechanical strain ε. The gauge factor is defined as: where. ε = strain = = absolute change in length.
Why is a strain gauge important?
The strain gauge is one of the most important sensor of the electrical measurement technique applied to the measurement of mechanical quantities. Thus, strain gauges can be used to pick up expansion as well as contraction. The strain of a body is always caused by an external influence or an internal effect.
What is the principle of electrical strain gauge and load cell?
In a tension load cell, the gauge is stretched and becomes longer and thinner. In response to the body shape changes, the strain gauges also change shape. This, in turn, causes a change in the electrical resistance of the strain gauge which can then be measured as a voltage change.
What is the use of strain gauge in load cell?
Use within Load Cells – strain gauges are used within load cells, the measure the strain and stress the load cell is under to determine weight and quantities. They can also be incorporated into other sensors including pressure transducers to help with pressure measuring.
What is a gauge factor explain its importance?
The gauge factor is a proportional factor between the measured strain and the relative change in the bridge that can be measured by a suitable device supporting Wheatstone bridges, such as QuantumX MX1615B from HBM.
What is strain gauge and types?
The strain gauge is a passive transducer that converts the mechanical elongation and compression into the resistance strain. It is invented in 1938 by Arthur Claude Ruge and Edward E. In the geotechnical field, the strain gauges are the important sensors. …
What happens to the resistance of the strain gauge when it is being compressed?
A strain gauge takes advantage of the physical property of electrical conductance and its dependence on the conductor’s geometry. Conversely, when a conductor is compressed such that it does not buckle, it will broaden and shorten, which decreases its electrical resistance end-to-end.