Installation and Pressure Sensing
The pressure sensors are generally installed at key parts of the forklift’s hydraulic system, such as on the hydraulic cylinders and oil pipes. This is because these areas can directly reflect the pressure changes caused by the weight of the goods. When the forklift picks up the goods, the weight of the goods will increase the pressure of the hydraulic system. The hydraulic oil transmits the pressure, and the sensors can keenly detect the change in pressure. For example, when lifting heavier goods, the pressure inside the hydraulic cylinder increases, and the pressure on the sensors also increases accordingly.

Physical Signal Conversion
The pressure sensors mainly operate based on two physical effects. One is the piezoresistive effect. There are piezoresistive elements inside this type of sensor. When subjected to pressure, the resistance value changes, and the greater the pressure, the more obvious the change. By measuring the change in resistance value, the magnitude of the pressure can be known. The other is the piezoelectric effect. Piezoelectric materials are used, which generate an electric charge when under pressure, and the amount of electric charge is proportional to the pressure, so as to detect the pressure.

Electrical Signal Output and Processing
The sensors convert the pressure changes into electrical signals, such as changes in voltage or current. However, the output electrical signals are usually very weak and need to be amplified by an amplifier to make it easier for the subsequent circuits to identify and process. The amplified signals are transmitted to the controller of the forklift weight limiter. The controller converts the electrical signals into weight values according to the preset algorithm and displays them on the display screen in the cab, allowing the driver to keep track of the weight of the goods in real time.

Overload Judgment and Safety Warning
A safe weight threshold is set in advance in the controller based on the rated load capacity of the forklift. It will compare the calculated actual weight with this threshold. Once the actual weight exceeds the threshold, it means that the forklift is overloaded. At this time, the controller will immediately trigger the alarm device to emit audible and visual signals to remind the driver to stop the operation or reduce the weight of the goods to ensure the safe operation of the forklift.