Load cell is a passive transducer or sensor which converts applied force into electrical signals.
- They are also referred to as Load transducers.
- There are many varieties of load cells, strain gauge based load cells are the most commonly used type.
- Load cells use different operating principles.
- 1.Load Cells based on fluid pressure.
- 2.Load Cells based on elasticity.
- 3.Load Cells based on magnetostriction effect or piezoelectric effect.
- Load cell primarily consists of a spring material and strain gauge.
- Spring material causes strain due to applied load and strain gauge changes its resistance in accordance with the change in strain.
- A mechanical arrangement, the force being sensed deforms a strain gauge.
- The strain gauge measures the strain as an electrical signal.
- A load cell usually consists of four strain gauges in a Wheatstone bridge configuration.
- Load cells of one strain gauge (quarter bridge) or two strain gauges (half bridge) are also available.
- The electrical signal output is typically in the order of a few millivolts and requires amplification by an instrumentation amplifier before it can be used.
- The output of the transducer can be scaled to calculate the force applied to the transducer.
Application
- Weight Machine.
Hardware Required

- Load Cell.
- ADC 0804.
- Instrumentation Amplifier.
- 8051 MicroController.
Circuit
