Strain gauge
A transducer which undergoes physical change in resistance as a result of strain produced by applying displacement, force or pressure
What is definition and formula for gauge factor
Ratio of the relative change in electrical resistance of a conductor to the applied relative change in conductor length
G.F = (🔺R/Rnominal)/(🔺L/Loriginal)
= (🔺R/Rnominal)/Strain Axial)
Wheatstone bridge
An arrangement of resistors of similar values such that a voltage presents itself when one of the resistor values changes even slightly
What is a problem with Wheatstone quarter bridge?
Changes in temp of material under test correspond to changes in the resistance and negatively impact the accuracy of the strain measurement because the resistance of a wire changes with temp.
What happens when inserting a strain gauge to a Wheatstone bridge?
Current flow through the gauge results in power dissipation and self-heating. this self-heating causes unwanted changes in temperature and therefore resistance which cannot be avoided. Solution is to use a Wheatstone half bridge circuit.
