The examination conditions of the environmental adaptability of the weighing sensor are the requirements for the range stability and durability of the weighing sensor in the OIML International Recommendation R60-1Edition2017 (E-cn) "Weight Sensor Measurement Requirements", that is, "the ability to output within the measuring range of the sensor after a period of time" and "the sensor shall have appropriate durability to meet the expected use of the weighing sensor", and stipulate several test contents, including: 3.1.7 performance test "test whether the sensor can complete the specified function";3.7.16 significant durability error, that is, "the durability error exceeding the corresponding recommendations";3.7.18 range stability, that is, "the ability to output within the measuring range of the sensor after a period of time";3.7.19 the influence of temperature on the minimum static load output, that is, "the change of the minimum static load output signal caused by the change of ambient temperature"; the influence of temperature on sensitivity, that is, "the change of sensitivity caused by the change of ambient temperature".The above test content can be understood as the indispensable examination for the range stability and long-term reliability of the weighing sensor.Because after a period of time to use the output capacity of the weighing sensor within the measuring range, it is actually the stability of the output sensitivity of the weighing sensor, and the stable output sensitivity can ensure the reliable operation of the weighing sensor. According to the definition of product reliability and the actual application of weighing sensors, the reliability can be understood as the ability or probability of weighing sensors to complete the specified functions under specified operating conditions and within a certain period of time.Specifically, it is the ability of weighing sensors to maintain their technical performance and work stably under specified operating conditions and within a certain period of time, which is measured by trouble-free working time or reliable life.Weighing sensors are mainly used in various electronic weighing instruments and electronic weighing systems, which require good and stable comprehensive performance, that is, the sum of nonlinearity, hysteresis error and sensitivity temperature effect, which should be within the maximum allowable error band in order to accurately complete the weighing and measuring task.The range stability of weighing sensors can be divided into initial instability period, stable period and fatigue instability period.The initial instability period is caused by the residual stress generated by elastic components after forging, mechanical processing, heat treatment and surface grinding, sandblasting, SMT and other processes, and the constant relaxation and release, which changes the zero point and sensitivity, resulting in the performance fluctuation of weighing sensors. It can be through the implementation of environmental stress screening of components, the aging and stabilization of weighing sensors, as far as possible to release and eliminate residual stress, in the production process through the initial unstable period, after the factory began to enter a stable period of stable and reliable work.After a long period of trouble-free work, due to the aging of protective sealing materials, circuit compensation and adjustment of components loss, resistance strain gauge fatigue and other reasons, the performance of the weighing sensor fluctuates, the work is unstable until failure, called fatigue instability period.Only by adopting a scientific and effective protective sealing and stability treatment process, to ensure that the weighing sensor has a stable working period to meet the stability and reliability requirements, to meet the relevant requirements of OIML international recommendations R60-1, R60-2 (2017) "weighing sensor metrology requirements". The stability and reliability of weighing sensors are crucial for all kinds of electronic weighing instruments and electronic weighing systems, which determine the stability of the whole product and system.Although OIML international recommendations R60-1Edition2017 (E-cn) "weighing sensor metrology requirements" put forward requirements for the range stability and durability of weighing sensors, and stipulated several test content, but at present there is no unified test method for the range stability and durability of weighing sensors at home and abroad. The weighing sensor manufacturing enterprises in the world all admit that the range stability is an important quality index, but it is rare to give the range stability index in the product samples and instructions.How to know the range stability of the weighing sensor?We can learn from the definition and requirements of the stability of the space load sensor to discuss this problem, that is, the change degree of the zero and sensitivity of the weighing sensor in a certain period of time and under the same conditions, or the stability of the zero and sensitivity.The so-called zero stability is the maximum change of the zero output of the weighing sensor in a certain period of time and under the same conditions.When testing the zero, there should be at least 10 times of data with basic equal time intervals within the specified time, and the maximum and minimum values are calculated.The so-called sensitivity stability is the relative change of the sensitivity of the weighing sensor in a certain period of time and under the same conditions.Tracking test is an economical and simple method for studying the reliability of the weighing sensor. Some enterprises at home and abroad have carried out two kinds of work in this respect.One is to track and test the storage life of the weighing sensor under laboratory environmental conditions.One is to track and test the trouble-free working time, that is, the service life, of the weighing sensor under the use of environmental conditions. It is suggested that the production enterprises and the use of units closely cooperate with each other to exchange information, accumulate reliability data such as the trouble-free working time of the weighing sensor.
 In order to ensure that the weighing sensor has excellent environmental adaptability, it is necessary to predict the working life of the weighing sensor under the use conditions.In many international academic conferences and academic exchanges, the experts agree that the working principle, structural characteristics, manufacturing process and application conditions of the weighing sensor, it should belong to the semi-permanent working device, IP67, IP68 protective seal grade of the weighing sensor should be able to work stably and reliably for more than 10 years, which is the standard that the environmental adaptability of the weighing sensor should reach.
 In recent years, due to the more reasonable structure of the elastic element of the weighing sensor, the circuit compensation technology and process are more perfect, the necessity of greatly improving the accuracy of the weighing sensor has relatively weakened. As a highly applicable device, to solve the problems in the application process and improve the environmental adaptability is the obvious characteristics of the development of the weighing sensor technology in recent years.The research topic is mainly reflected in the optimal design of the overall structure of the weighing sensor, the technology-intensive combination between the elastic element and the pressure head introduced by the load, the cushion bearing the load and the installation platform; Supporting the scientific application and integration of processes, basic processes, core processes and special processes. In addition to solving the problem of the stability of the internal mechanism of the weighing sensor, special attention should be paid to the adaptability of the weighing sensor to the external environmental conditions, that is, the adaptability of the objective environmental conditions and the inductive environmental conditions. Therefore, we must pay attention to the design of the environmental conditions of the weighing sensor, the reliability design, control and management, strengthen the research of the protection and sealing technology and process, and improve the long-term stability and working reliability of the weighing sensor as soon as possible, so as to keep up with the development trend of the international weighing sensor and stay in an invincible position in the fierce competition at home and abroad.