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MTBF certification
发布日期：2021-11-06阅读量：603发布者：超级管理员
Introduction to certification
MTBF certification refers to the certification of the mean time between failures (MTBF) of a product, and its full English name is "mean time between failure". In fact, MTBF refers to MTBF test report, which is the report of product reliability prediction. MTBF is the reliability index of a product (especially electrical products). The unit is "hour". It reflects the time quality of the product and reflects the ability of the product to maintain its function within the specified time. Specifically, it refers to the average working time between two adjacent faults, also known as the average fault interval. Generally speaking, the product with less failure is high reliability. The ratio of the total number of failures to the total number of life units is called "failure rate". It only applies to Repairable Products. At the same time, the ratio of cumulative working time to failure times is also stipulated as MTBF. Generally, the MTBF of disk array products should not be less than 50000 hours.
MTBF data calculation
7 (DOD reliability analysis center and Rome laboratory proposed and become the industry standard for military products), GJB / z299b (Chinese military standard) and Bellcore (at & T Bell laboratory proposed and become the industry standard for MTBF of civil products).
In MTBF calculation, the failure rate of each component in the product is mainly considered. However, the failure rate of devices varies greatly in different environments and service conditions, so these factors must be considered when calculating reliability indexes. These factors can hardly be calculated manually, but with the help of software such as mtbfcal and its huge parameter library, MTBF value can be easily obtained. The MTBF of the machine tool must be more than 4500 hours if the plant working three shifts a day is required to operate continuously for 24 hours and the failure free rate P (T) = 99%. MTBF 5000 hours requires higher and more complex production lines composed of different numbers of CNC machine tools. Here we only discuss single machine tool:
If the failure rate ratio between the host computer and the CNC system is 10:1 (the reliability of the CNC system is an order of magnitude higher than that of the host computer), the MTBF of the CNC system will be more than 50000 hours, and the MTBF of the main parts such as the CNC device, the spindle and the driving part must be greater than 100000 hours.
MTBF is not detected in actual operation, it is converted by national standard detection algorithm. For example, the 60000 hour MTBF of Lenovo Yangtian is to apply comprehensive environmental stresses such as voltage, temperature and humidity to the tested products at a specific frequency during a 40 day experimental period by sending 192 Lenovo Yangtian computers for inspection. According to the corresponding relationship between the reliability of electronic products and the time characteristics, the experimental results are converted into standard data models. Similarly, the 100000 hour MTBF beyond e350 of Tongfang was converted from 400 computers through 18 days' test results.
Telcordia SR 232
National military standard GJB / Z 299B
Application for MTBF information
Product BOM Product specification Product service conditions Do the corresponding test to obtain temperature rise, current or voltage data
