A Detailed Explanation of Each Component of the Dynamic Checkweigher

2024-11-01

• Function: The weighing sensor is the core component of the dynamic checkweigher. It is responsible for converting the weight signal of the product into an electrical signal and transmitting it to the controller for processing.
• Working Principle: Weighing sensors usually adopt the principle of resistance strain gauge. When a product is placed on the sensor, the elastic body inside the sensor deforms, and the strain gauges attached to the elastic body also generate strain accordingly, resulting in a change in the resistance value. By measuring the change in the resistance value, the weight of the product can be calculated.
• Types: Common weighing sensors include single-point type, cantilever beam type, S-shaped beam type, etc. Different types of sensors are applicable to different weighing ranges and accuracy requirements.
• Accuracy and Stability: The accuracy and stability of the weighing sensor directly affect the measurement accuracy of the dynamic checkweigher. High-quality weighing sensors possess characteristics such as high accuracy, high stability, and strong anti-interference ability, enabling them to work stably for a long time in harsh working environments.

• Function: The conveyor is responsible for transporting the products to the weighing sensors for weighing and then transporting the weighed products to the next process.
• Types: Conveyors mainly include belt conveyors, roller conveyors, chain plate conveyors, etc. Different types of conveyors are suitable for different product shapes and transportation requirements.
• Speed Control: The speed of the conveyor can be adjusted according to production requirements. Generally speaking, the faster the speed, the higher the production efficiency, but the measurement accuracy may be affected to some extent. Therefore, when selecting the conveyor speed, it is necessary to comprehensively consider the requirements of production efficiency and measurement accuracy.
• Material and Structure: The material and structure of the conveyor should be selected according to the characteristics of the products. For example, in the food industry, the conveyor should be made of food-grade materials, with a smooth surface and easy to clean; in the chemical industry, the conveyor should have characteristics such as corrosion resistance and wear resistance.

• Function: The controller is the brain of the dynamic checkweigher. It is responsible for receiving the weight signals transmitted from the weighing sensors, processing and analyzing them, and controlling the work of components such as conveyors, displays, and rejection devices.
• Working Principle: Controllers usually adopt microprocessors or programmable logic controllers (PLC) as the core control units and implement various control functions through software programming. The controller can perform processing such as filtering, amplifying, and A/D conversion on the weight signals, calculate the weight of the product, and compare it with the preset weight range to determine whether the product is qualified. If the product is not qualified, the controller will send a signal to control the rejection device to reject the unqualified product.
• Functional Characteristics: The controller has various functional characteristics, such as automatic calibration, automatic zero clearing, data storage, report generation, and communication interfaces. The automatic calibration function can ensure the long-term stability of the measurement accuracy of the dynamic checkweigher; the automatic zero clearing function can eliminate the zero drift of the conveyor and the weighing sensor; the data storage and report generation functions can facilitate users to conduct statistical analysis of production data; the communication interface can realize communication with the host computer or other devices to achieve automated production control.

• Function: The display is used to show information such as the weight of the product and whether it is qualified, facilitating operators to observe and monitor the production process.
• Types: Displays mainly include LED display screens, LCD display screens, etc. Different types of displays have different display effects and characteristics.
• Display Contents: The display can show the actual weight of the product, the preset weight range, whether it is qualified, the production speed, the cumulative output, etc. Some high-end displays can also show statistical charts, fault alarm information, etc.
• Operation Interface: The operation interface of the display should be simple and intuitive, facilitating operators to set and operate. Generally speaking, the operation interface can be operated through keys, touch screens, etc.

• Function: The rejection device is used to remove unqualified products from the production line to ensure product quality.
• Types: Rejection devices mainly include air-blowing type, push-rod type, swing-arm type, etc. Different types of rejection devices are suitable for different product shapes and rejection requirements.
• Working Principle: When the controller determines that a product is unqualified, the rejection device will receive a signal and initiate the corresponding rejection action. For example, the air-blowing type rejection device blows unqualified products away from the production line by compressed air; the push-rod type rejection device pushes unqualified products out of the production line by a push rod; the swing-arm type rejection device moves unqualified products away from the production line by a swing arm.
• Speed and Precision: The speed and precision of the rejection device should match the speed of the conveyor and the measurement precision of the dynamic checkweigher. If the rejection speed is too slow or the precision is not high, it may lead to the omission or mis-rejection of unqualified products, affecting product quality.