A load cell is a mechanical sensor that converts the force or weight applied to it into an electrical signal. The strain gauge elements inside change shape under load, changing their resistance, and this change is converted into a measurable voltage through a Wheatstone bridge circuit. It cannot be used directly with Arduino alone; it needs an amplifier module like the HX711 to amplify the signal. It is available in the market with different capacity options such as 1kg, 5kg, 10kg and 50kg. It is used with the HX711 in projects that require precise weight measurement such as digital kitchen scales, post office scales and industrial filling systems.
