In the context of the rapid development of Industry 4.0 and intelligent manufacturing, automatic measurement systems have become a key technology to promote the improvement of production efficiency and ensure product quality in various industries. From precise proportioning of chemical raw materials, to quantitative packaging of food and beverages, to precise measurement of energy resources, automatic measurement systems, with their high precision, automation, and intelligence, run through multiple links such as production, trade, and scientific research, reshaping traditional measurement models and providing solid support for the development of modern industries.

1、 Definition and Core Principles of Automatic Measurement System

Automatic measurement system is a comprehensive system that automatically measures, calculates, controls, and processes physical quantities (such as mass, volume, flow rate, length, temperature, pressure, etc.) through the collaborative operation of sensors, controllers, actuators, and data processing units. The core principle is based on the conversion of physical quantities and signal processing, which converts the measured physical parameters into processable electrical or digital signals, and then calculates accurate measurement results through algorithms.

Taking quality measurement as an example, common resistance strain gauges work by utilizing strain effects. When an object is placed on the weighing platform, the elastic body inside the sensor undergoes deformation, and the resistance strain gauge attached to it changes its resistance value accordingly. The resistance change is converted into a voltage signal through a Wheatstone bridge, amplified and A/D converted into a digital signal, and finally the mass of the object is calculated by the control system. Other types of measurement, such as electromagnetic flow meters based on the principle of electromagnetic induction in flow measurement and ultrasonic flow meters utilizing ultrasonic propagation characteristics, all follow similar physical conversion and signal processing logic to achieve accurate measurement of different physical quantities.

2、 The core components of an automatic metering system

（1） Sensor unit: the "perception organ" of the system

Sensors are the source of data acquisition for automatic measurement systems, and can be classified into various types based on the different measurement objects:

Weighing sensors: including resistive strain gauges, capacitive sensors, piezoelectric sensors, etc. Among them, resistive strain gauges have become the preferred choice for material weighing, batching, and other scenarios due to their high stability and accuracy of up to 0.01% FS (full range).

Flow sensors: such as electromagnetic flow meters (suitable for conductive liquids, accuracy ± 0.5%), turbine flow meters (commonly used in petrochemicals), ultrasonic flow meters (non-contact measurement, suitable for large-diameter pipelines).

Displacement and length sensors: Grating rulers, magnetic grating rulers, etc. are commonly used in mechanical processing and automated assembly, with a resolution of up to micrometers, ensuring accurate measurement of part dimensions.

Other sensors: temperature sensors (such as thermocouples, thermistors), pressure sensors (piezoresistive, capacitive), etc., used to monitor environmental or process parameters.

（2） Controller unit: the "decision-making center" of the system

The controller is responsible for receiving sensor signals, performing calculations, analysis, and processing, and issuing control instructions according to preset programs. Common controllers include programmable logic controllers (PLC) and industrial computers (IPC):

PLC: With its high reliability, strong anti-interference ability, and flexible programming characteristics, it is widely used in industrial automation measurement scenarios, and can achieve logic control, data processing, and equipment linkage.

IPC: Suitable for scenarios that require complex algorithms and big data processing, such as high-precision dynamic weighing systems and intelligent warehouse measurement management, it can integrate artificial intelligence algorithms to optimize measurement strategies.

（3） Execution mechanism unit: the "operating arm" of the system

The executing mechanism completes corresponding actions according to the controller instructions to achieve metrological control. For example, in an automatic batching system, actuators such as electric valves, screw conveyors, and belt scales accurately control the conveying volume based on the material ratio calculated by the controller; In the filling system, the cylinder driven filling head precisely controls the liquid injection amount based on the measurement results.

（4） Display and Data Processing Unit: System's "Interactive Interface"

This unit displays measurement results through devices such as touch screens and LED displays, allowing operators to view data and set parameters in real-time. At the same time, the system has data storage, analysis, and transmission functions, and uploads data to the factory management system (MES) or cloud platform through network interfaces (Ethernet, RS485, etc.), supporting production data statistics, quality traceability, and remote monitoring.

3、 Typical application scenarios of automatic metering systems

（1） Industrial production field

Chemical industry: In the production of coatings, rubber, plastics, etc., automatic metering systems precisely control the ratio of raw materials to ensure stable chemical reactions. For example, in the production of lithium batteries, the input of positive electrode materials, electrolytes, etc. is controlled through high-precision weighing and flow measurement to ensure the consistency of battery performance.

Food and beverage industry: used for quantitative packaging and filling of products, such as beverage production lines that control filling volume errors within ± 1% through flow meters and weighing sensors; In the production of baked goods, automatic measurement of raw materials such as flour, sugar, oil, etc. is used to ensure consistent product taste.

Pharmaceutical industry: Strictly following GMP standards, using high-precision measuring equipment to ensure accurate drug composition, such as capsule filling machines that use weight detection and automatic exclusion functions to ensure that the drug content of each capsule meets the standard.

（2） In the field of commercial trade

Gas station: The automatic metering system inside the gas dispenser uses flow sensors and electronic controllers to accurately measure the fuel volume and display the amount, ensuring fair transactions.

Logistics warehousing: Electronic weighing scales and automatic sorting and weighing equipment achieve fast and accurate measurement of goods, improve logistics efficiency, and reduce labor costs.

（3） In the field of energy and environmental protection

Energy metering: In natural gas and electricity transmission, automatic metering systems monitor flow and consumption in real-time, providing data support for energy settlement and energy consumption analysis. For example, ultrasonic flow meters are used for long-distance natural gas pipelines to achieve high-precision and pressure loss free measurements.

Environmental monitoring: Sewage treatment plants monitor sewage flow through flow meters and detect pollutant concentrations through sensors such as COD and ammonia nitrogen, providing a basis for process regulation and environmental supervision; The air quality monitoring station uses automatic measuring equipment to detect real-time indicators such as PM2.5 and sulfur dioxide.

4、 The Technological Development Trend of Automatic Measurement System

Intelligent upgrade: Integrating Internet of Things (IoT), big data, and artificial intelligence technologies to achieve fault prediction, automatic calibration, and adaptive control. For example, analyzing historical data through machine learning algorithms, optimizing measurement strategies, and improving system stability.

High precision and dynamic measurement: Develop higher precision sensors and algorithms to meet the stringent requirements of high-end manufacturing (such as semiconductors, aerospace) for metrology; Strengthen research on dynamic measurement technology to achieve precise measurement of rapidly moving objects.

Multi functional integration and modular design: Integrating multiple measurement functions into one, reducing equipment costs and installation space; Adopting modular design, it facilitates system expansion and maintenance, and adapts to different production needs.

Green energy conservation and sustainable development: Developing low-power sensors and energy-saving actuators to reduce system energy consumption; Optimize measurement algorithms, reduce material waste, and help enterprises achieve green production.

As the core technology of modern industrial and commercial activities, automatic measurement systems are constantly developing towards intelligence, high precision, and multifunctionality. Its widespread application not only improves production efficiency and product quality, but also lays a solid foundation for digital transformation and sustainable development in various industries.