A basic strain gauge is a type of sensor used in force and weight measurement applications. Its function is to measure the strain or deformation in an object when subjected to a force, and from this measurement, determine the applied force or weight.
Here's how a basic strain gauge works in force and weight measurement:
Principle of Strain Measurement: Strain is the relative change in length or shape of an object when it is subjected to an external force. When a force is applied to an object, it causes it to deform slightly. Strain gauges are designed to detect this deformation.
Strain Gauge Construction: A strain gauge is typically a thin metallic foil or wire that is attached to the surface of the object to be measured. As the object experiences deformation due to the applied force, the strain gauge also stretches or compresses along with it.
Resistance Changes: The metallic foil or wire used in the strain gauge is chosen for its electrical properties. When it is deformed, its electrical resistance changes. As the gauge stretches, its length increases, leading to an increase in resistance, and when it compresses, its length decreases, leading to a decrease in resistance.
Wheatstone Bridge Circuit: To measure the tiny resistance changes in the strain gauge accurately, it is connected in a Wheatstone bridge circuit. The bridge circuit is a network of resistors that provide a more sensitive way of detecting changes in resistance.
Output Voltage: When the Wheatstone bridge is energized with a constant voltage, the strain gauge's resistance change causes an imbalance in the bridge circuit. As a result, an output voltage is produced, which is proportional to the applied force or weight and indicates the magnitude of the deformation.
Calibration: Before using a strain gauge in force and weight measurement applications, it needs to be calibrated. Calibration involves relating the measured output voltage to known forces or weights. By knowing the calibration curve, the force or weight corresponding to the output voltage can be accurately determined.
Applications: Strain gauges are used in a wide range of applications, including load cells for weighing systems, force transducers in material testing, stress analysis in structural engineering, and various industrial and research applications where force or weight measurements are required.
Overall, a basic strain gauge's function is to convert the mechanical deformation caused by the applied force into an electrical signal, allowing for accurate and reliable force and weight measurements.