Strain gauge load cells are the basic components of various types of electronic weighing instruments. Their accuracy, stability and reliability are critical to the weighing of electronic weighing instruments.
Accuracy plays a decisive role. There are many types of electronic weighing instruments in our country and they are widely used, not only involving domestic and foreign trade settlements, but also involving the interests of consumers. Electronic weighing instruments used in key fields are legal measuring instruments mandated by the state. Some electronic scales must also work under relatively harsh environmental conditions, which requires that the load cells used in such electronic scales must not only meet the corresponding accuracy level requirements, but also have high environmental adaptability. According to the nature and characteristics of the environment in which electronic weighing instruments are used, general environmental conditions are divided into two categories: objective environment and induced environment. The former is the surrounding natural environment, and the latter is the man-made environment. The environmental conditions that electronic scales can withstand are both, mainly temperature, humidity, vibration, impact, power supply and various electromagnetic compatibility interferences. According to the consensus of domestic and foreign load cell and electronic scale manufacturing enterprises, the environmental adaptability index of the weighing sensor is generally implemented in the range stability and long-term reliability of the weighing sensor itself.
Accuracy, stability and reliability are important quality indicators of load cells, among which stability and reliability are the foundation. Without stability and reliability, there is no accuracy. The performance of a load cell varies with the following three factors: structural design, manufacturing process, and testing and calibration. Its environmental adaptability, that is, the range stability and working reliability of the weighing sensor, is determined by the protective sealing and stability treatment process.
Regarding the range stability of the weighing sensor, it is: "The energy output of the weighing sensor within the measurement range over a period of time is
Force" can be understood as the range stability of the load cell, that is, the degree of change in the sensitivity of the load cell under the same conditions within a certain period of time. The reliability of the load cell is defined as "the requirement that the load cell should have appropriate durability "Performance to meet the expected use of the load cell", the key point is to have appropriate durability to meet the expected service life of the load cell. It can be understood that the load cell maintains various properties under specified conditions of use and within a certain period of time. Technical performance and the ability to work stably can be measured by fault-free working time or reliable life. What the two have in common is how to withstand various environmental conditions that may be encountered and reflect its technical performance indicators stably and reliably. That is, the adaptability to environmental conditions. Therefore, it is necessary to pay attention to and understand the environmental conditions and their potential effects, and select a load cell that can resist the effects of these environmental conditions.
  Effect of environmental conditions on load cell performance: Whether electronic scales are used indoors or outdoors, they must withstand the dual effects of the objective environment and the sensing environment. The former is the natural environment around the application site of electronic weighing instruments, and the latter is the artificial environment when electronic weighing instruments are working. The main influences of the two are temperature, humidity, vibration, impact, power supply and various electromagnetic compatibility interference. The load sensor is in this way. If it should be able to work stably and reliably under certain environmental conditions, it is necessary to ensure that the load cell has high range stability and long-term reliability. This problem has long been a key technical issue that load cell manufacturers are committed to solving. Its essence is the stability of the load cell to external conditions, or environmental adaptability, mainly the stability of changes in temperature and humidity, and Corrosion resistant
corrosion, abrasion, vibration and impact resistance. The working principle, elastic element structure and manufacturing process of the load cell determine that it can withstand certain vibration and impact loads. When used in high and low temperature environmental conditions, it is equipped with special high temperature resistance and
Low temperature resistant load cell. Weighing sensors are generally used in electronic scales, and their operating temperature is -20 to 40°C. Therefore, the environment-resistant design is mainly designed to prevent moisture, salt spray, and mold. During use, the load cell is directly sprayed and soaked by water, and the infiltration of moisture will reduce the bonding strength and insulation resistance of the strain adhesive, because moisture is not entirely H20, but is usually many complex aqueous solutions that can penetrate Various polymers to plasticize and change properties
able. Salt spray is an aerosol-like substance whose main components are calcium chloride, magnesium chloride and other impurities. It has a strong corrosive effect on elastic components, resistance strain gauges and strain adhesives. This is the focus of load cell protection and sealing. If the protection and sealing are poor, all previous technological achievements will be wasted. Therefore, protection and sealing are key processes in the manufacturing process of load cells, and are the fundamental guarantee for load cells to withstand the influence of objective and induced environmental conditions and work stably and reliably. An effective way to improve environmental adaptability is to enhance the moisture-proof, waterproof, salt-spray-proof performance and vibration and impact resistance of the load cell.