Resistance strain gauge

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Resistance strain gauge

The working principle of strain gauge is based on Piezoresistive Effect. This is why it is also often called Pizoresistive Gauge.

Astrain gauge is sensor whose resistance varies with applied force; It converts force, pressure, tension, weight, etc into a change in electrical resistance which can then be measured. So by measuring the change in resistance we can measure force Pressure tension, weight etc.

Types

(1) wirewound
(2)Foil
(3) semiconductor

In wirewound type
(a) bonded
(b) unbonded


What is gauge factor?

The fractional change in resistance, (ΔR/R), divided by the fractional change in length, (Δl/l), is called the gauge factor, G. Note that G is a unitless number. Accordingly, the gauge factor provides sensitivity information on the expected change in resistance for a given change in the length of a strain gauge.

Gauge Factor:

Gauge Factor is defined as the ratio of per unit change in resistance to the per unit change in length. This can be mathematically written as,

 Gf = (ΔR / R) / (ΔL / L)





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