The loading scale is a highly automated liquid filling equipment, mainly used for filling liquid raw materials into designated containers according to the preset weight ratio. It is mainly composed of a liquid pump, an Electronic scale, a filling head, and a control panel. The liquid pump is responsible for transporting the liquid raw materials to the filling head, the electronic scale is responsible for real-time monitoring of the filling weight, and the control panel is responsible for setting the filling weight and controlling the equipment operation. The liquid pump transports the liquid raw materials to the filling head, the electronic scale monitors the filling weight in real time. When the filling weight reaches the preset value, the control panel will automatically stop the liquid pump from feeding, and at the same time close the filling head, completing the filling process. The Filling system collects signals such as speed, temperature, pressure, flow, valve opening and equipment operation status from the on-site weighing instrument, and realizes real-time and rapid information exchange with the human-machine interface through the RS485 interface. Through the centralized display of on-site process parameter measurement signals and the feedback of program control signals to the on-site execution process, it realizes the automatic control and adjustment of the production process temperature and pressure. By using the feeding weighing control, the required amount is set before feeding the liquid material, then press the start button, the valve automatically opens, the material pump automatically starts to transport the liquid material, when the liquid material reaches the set value, the liquid pump automatically stops, and the automatic control valve automatically closes, and the entire liquid material transportation process is completed automatically. 

The filling scale adopts an electronic scale control method. By controlling the accuracy of material addition, the automatic weighing accuracy is ensured. To ensure the accuracy of the electronic scale, the feeding method of "first fast then slow, and finally point movement" is adopted. The weight of the container itself (tare weight) on the electronic scale is deducted. After the feeding instruction is issued by the PLC, during the initial period of feeding, rapid feeding is carried out. When the detection reaches the target value of rapid feeding, slow feeding begins; when the detected filling weight reaches the advance amount of the target value, all the feeding valves are closed, and the target weight is achieved relying on the self-weight of the material. In the weighing control, the feeding valve is set in three states: "fully open", "partial open" and "closed". The "fully open" state is mainly used for coarse-precision feeding. When the feeding approaches the set value, the "partial open" action occurs. When it reaches the set value completely, the feeding valve is "closed". Through PLC control of the fast and slow feeding and point movement of feeding, as well as to eliminate the influence of air feeding on the weighing accuracy, the PLC's automatic correction of the pre-stop quantity of the filling gun and other control measures are adopted. To enable the PLC to obtain the status of the feeding valve, limit switches are installed at the feeding valve to feedback the opening/closing status of the feeding valve to the PLC. 

The quantitative scale operates based on the working principle of the electronic scale. When a container is placed on the scale platform, the pressure is exerted on the electronic scale, causing the sensor to deform, resulting in a change in impedance and a variation in the applied excitation voltage. An outputting analog signal with a changing pattern is generated. This signal is amplified by the amplification circuit and then sent to the analog-to-digital converter. It is converted into a digital signal that is easy to process and sent to the CPU for operation and control. The CPU, based on the keyboard command and the program, outputs this result to the weighing display. After the container passes through the conveying system and enters the scale, an analog signal for weighing is generated by the pressure sensor and input to the analog input module of the PLC, which is then converted into a digital quantity. When the value read by the PLC from the analog input board is equal to the preset target value, the filling gun stops feeding. 

The main function of the Weighing system is to precisely weigh, measure, collect data, communicate, automatically generate a database, automatically generate label information and inkjet information, and display real-time production data after the container passes through the Filling machine. The PLC sends weighing instructions and the amount of liquid to be added to this electronic scale. Above the electronic scale is the filling gun for the liquid filling, which controls the filling amount. During weighing, the entire automatic filling machine controls the amount of liquid added. When the added amount reaches the set amount, the weighing ends and the liquid is injected into the next container. Through the control of the electronic scale by the PLC and communication with the PLC, the liquid is mixed according to the specified sequence and weight by the PLC, and the actual weight of the weighing is fed back to the PLC in real time.