ISO 16750-1:2018 pdf free

ISO 16750-1:2018 pdf free.Road vehicles – Environmental conditions and testing for electrical and electronic equipment
Using real-time life tests or accelerated life tests (with corresponding load increase), the design can be checked for functional loads combined with further environmental loads in order to discover design weaknesses. Generally, only a small number of DUT is sufficient to achieve this. This case is by far the most frequent. However, the results are not suitable for deriving a statement on reliability as the number of DUT is too low for a statistically correct statement.
Determining reliability is a totally different task. The following step-by-step method is suggested:
1) Determine the type of load which is relevant for service life and specific to the product and determine the test to be conducted.
2) Determine the in-practice load, for example running time, mean temperature, etc.
3) Specify the survival probability and confidence levels and calculate the necessary number of DUT or a test duration on the basis of in-practice load, based on statistical correlation. Generally, this calculation requires extensive testing.
4) A reduction of this extensive testing resulting from step 3 to feasible values can be performed by a permissible increase of load on the basis of an appropriate correlation between in-practice experience and testing. The increase in load should not lead to a change of the expected damage process. Generally, compared to the check of potential design weaknesses, considerably more extensive testing will be required.
It is recommended to use the step-by-step method also in the first case for checking design. However,step 3 is then omitted (statistics calculation).
When applying this correlation, two conditions should be met:
一There should be no failures during testing; if failures occur, only the test duration up to the first failure should be used for the calculation.
一Failures expected in practice should have Weibull distribution.
Depending on the task, the equation described above should be solved to give the required quantity,other quantities should be known. If this is not the case, these quantities should be determined by experiment or by using figures based on experience.
In the following, the method is explained by using an example.ISO 16750-1 pdf download.