All weighing sensors and electronic weighing systems composed of weighing sensors will experience performance fluctuations over time or use, fail to complete the specified functions and eventually fail (unstable). The time from the beginning of use to the failure of a weighing sensor is uncertain. Reliability is to study the average trouble-free working time, working failure rate and reliable life of the weighing sensor under specified conditions and time, which is crucial to improving the reliability of electronic weighing instruments and electronic weighing systems assembled with weighing sensors. Therefore, reliability has become an important quality indicator of weighing sensors and a major symbol of market competition.
The International Organization for Standardization (ISO8402) defines reliability as: "The ability of a unit to complete the specified functions under given environmental and operating conditions and within a given time." Here, the word "unit" refers to the object considered as a whole, which can be a component, a subsystem, or a system. Considering a weighing sensor alone, it is a component, and considering it together with a weighing system, it is an important link in a subsystem or system. "Time" should be understood from a broad perspective. For a weighing sensor or an electronic weighing instrument, it is the number of stress cycles. Definition of quality: "The quality of a product reflects the sum of the characteristics of the product's ability to meet explicit and implicit needs." According to the definition, "needs" can include performance, availability, credibility, reliability, etc. Here, "performance" is one aspect of needs and the central consideration, while reliability is the ability of the product to complete the specified function under specified conditions and within a specified time. According to the above definition, the state of being unable to complete the specified function is called failure or failure. The core of reliability is failure, that is, reliability is caused by the failure of the product. Failure-failure-reliability-reliability, the four are closely related and constitute a cause-effect chain. From the above reliability theory, it can be concluded that the reliability of the weighing sensor is the continuous working time without failure under specified environmental conditions. Reliability is caused by the failure of the weighing sensor. Reliability is a value used to measure the reliability level of the weighing sensor. It is the result of data processing based on the statistical working time and failure number of the weighing sensor. If a higher reliability level is to be achieved, the reliability design, control and management of the weighing sensor must be done well.
Section 1 Reliability of strain gauge weighing sensor
Since the 1990s, weighing sensors and electronic scales in my country have been widely used in industrial and commercial weighing and measurement. The stability and reliability issues of weighing sensors have increasingly attracted the attention of users. Under current conditions, it is not difficult to develop and produce weighing sensors with higher accuracy levels, but it is not easy to develop and produce weighing sensors with higher stability and reliability. In many international academic conferences and academic exchanges, experts from various countries unanimously agreed that in terms of the working principle, structural characteristics, manufacturing process and application conditions of weighing sensors, it should be a semi-permanent working device, and weighing sensors with IP67 and IP68 protection sealing levels should be able to work stably and reliably for more than 10 years.
According to the definition of product reliability and the actual application of weighing sensors, its reliability is defined as: the ability or probability of a weighing sensor to complete the specified function under the specified conditions of use and within a certain period of time. Specifically, it is the ability of a weighing sensor to maintain its various technical performances and work stably under the specified conditions of use and within a certain period of time, which is mostly measured by trouble-free working time or reliable life. As we all know, weighing sensors are mainly used in various electronic scales and electronic weighing systems, requiring good and stable comprehensive performance, that is, the sum of all deviations such as nonlinearity, hysteresis error and sensitivity temperature effect should be within a certain allowable error band. Among them, the stability of zero point and sensitivity directly affects the long-term stability and working reliability of weighing sensors.