I. Overview 1 Several related terms: Durability: The ability of a weighing instrument to maintain its performance characteristics unchanged throughout its entire specified service life. Range stability: The ability of a weighing instrument to maintain the difference between the maximum weighing capacity indication and the zero point indication within the specified limit within the prescribed service life. Long-term stability: The ability of a weighing instrument to maintain its performance characteristics within the specified service life. Durability test: When conducting a durability test, the weighing instrument should be able to maintain its performance within the maximum allowable error range during use at the "final" test. And the difference between the error value measured at the beginning of the durability test (" first "test) and that measured at the end of the durability test (" final" test) shall not exceed the absolute value of the maximum allowable error for inspection during use. Range stability test: A test conducted to prove that the weighing instrument under test can maintain the stability of its range. Long-term stability test: A test to detect that the metrological performance of a weighing instrument can still meet the inspection indicators during use without any adjustment after the specified verification cycle. First, let's take a look at the differences among the terms "durability", "range stability", and "long-term stability". Although the descriptive language used for each noun may vary, the meanings they convey are basically the same, all aiming to ensure that the metrological performance of weighing instruments does not exceed the specified indicators within the prescribed service life. However, the methods for the "range stability test" and the "long-term stability test" are different. Both the "durability test" and the "long-term stability test" separately assess the results of the first verification and the two tests conducted during use. The difference lies in that the "durability test" does not exceed the absolute value of the maximum allowable error during use inspection. The "Range stability test" in the International Recommendation R76 "Non-Automatic Weighing Instruments" stipulates: The test was conducted under fully stable environmental conditions (normal and stable laboratory environmental conditions). Before, during and at different intervals after the temperature test, damp heat test and voltage change test of the scale under test, at least 8 loads close to the maximum scale capacity (Max) were applied, and the changes in error were observed. For any one of the n measurements, the variation in the indication error should not exceed half of the verification division value or half of the absolute value of the maximum allowable error for the first verification under this test load, and the larger of the two should be taken. In JJF1333 "Outline for Type Evaluation of Digital Indicator Rail Scales", the "Long-Term Stability Test" is stipulated as follows: After the first test at the usage site is qualified, the devices that affect the metrological performance should be sealed as necessary. The test sample machine should ensure stable operation within one verification cycle. Without any adjustment, tests such as zero setting accuracy, repeatability, eccentric load, and weighing performance should be conducted. The metrological performance should comply with the regulations for inspection during use. The differences between the two lie in: (1) The "range stability test" is conducted in a "laboratory", and the eight tests are interspersed among several influencing factor tests; (2) The "long-term stability test" is conducted at the "actual usage site". Under the condition that no adjustments are allowed after the initial verification, the weighing instrument under test is inspected during use after one cycle. 2 The relevant international recommendations stipulate in Table 7 of R76-1's 3.10.2.1 that all the error distribution coefficients for "range stability" are assigned to the "weighing indicator". If analyzed in this line of thinking, it indicates a problem, that is: When large-scale weighing instruments undergo "type evaluation tests" using the modular method, it is only necessary to conduct "range stability" tests on the "weighing indicator", and it can be considered that the stability of the entire system has been guaranteed. However, Appendix B specifically dedicates a chapter to explaining how to conduct the "range stability test" for the entire machine. In Table 12, it is stipulated that the impedance connected during the test should be "low resistance". Here, it can be understood that when conducting the "range stability" test on the "weighing indicator", only one low-resistance analog sensor needs to be connected. It can also be understood as the need to conduct performance tests on the entire weighing system. We understand that the stability of any module in a system cannot represent the stability of the system. It is inappropriate to simply assign all the errors of "range stability" to the "weighing indicator". Therefore, this issue should be promptly fed back to the relevant drafting body of the International Organization of Legal Metrology, requesting them to modify the relevant content.