This standard is issued under the fixed designation B; the number 1 This test method is under the jurisdiction of ASTM Committee B08 on Metallic. ASTM B_机械/仪表_工程科技_专业资料。 Designation: B – 88 ( Reapproved ) Standard Test Method for Attribute Sampling. Purchase your copy of ASTM B – 88() as a PDF download or hard copy directly from the official BSI Shop. All BSI British Standards.
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For this reason, there are no AQL, etc.
ASTM B – 90() Standard Test Method of Variables Sampling of Metallic and Inorganic Coatings
It is the worst condition that can occur under rectifying inspection. Sampling plans based on inspection by variables are given in Test Method B Therefore, basic to any sampling inspection plan is the willingness of the buyer to accept lots that contain some nonconforming articles. Individual reprints single or multiple copies of this standard may be obtained by contacting ASTM at the above address or at phonefaxor service astm. Accept and continue Learn more about the cookies we use and axtm to change your settings.
ASTM B602 – 88(2016)
Throughout this method, it g602 assumed that no mistakes are made in sampling, measurement, and calculation. So the selection of a sampling plan involves the balancing of the costs of inspection against the consequences of accepting an undesirable number of nonconforming articles.
The specic plans selected are identied in Tables of this test method. The specific plans selected are identified in Tables 1- 3 of this test method.
If the sample is consistently a signicant part of the lot, the correct AOQL will be smaller than the astmm value. In the extreme case of every article in an inspection lot being nonconforming, a sample will always indicate that the lot is unacceptable. The constant interval is 24 divided by For example, the articles may be expensive or the inspection lot may be small. When the incoming lots are of a good quality level, the average quality level of a series of lots will be even better when the rejected lots are screened and resubmitted.
Link to Active This link will always b6022 to the current Active version of the standard. You may experience issues viewing this site in Internet Explorer 9, 10 or The AQL is the quality level that is considered to be acceptable. Sampling plans based on inspection by variables are given in Test Method B This standard is subject to revision at any time by the responsible technical committee and must be reviewed every ve years and if not revised, either reapproved or withdrawn.
At intermediate quality levels of incoming lots, the average quality level of a series of accepted lots will again be improved, but it will not be improved as much as in either of the above cases; and there will be an intermediate quality level where the degree of improvement is the least. If only a few articles in an inspection lot are nonconforming, the sample probably will indicate that the lot is acceptable; but there is a small probability that the sample will indicate that the lot is unacceptable.
If the units have serial numbers, the serial numbers can be used. Using the arithmetic mean of these values, the standard deviation of the process, and the factor b62 that is found in the Tables, a number is calculated see 9.
Random numbers atsm be obtained from books pertaining to statistics. Also, Guide B describes the nature of attribute sampling plans and the several factors that must be considered in the selection of a sampling plan. The larger the sample, the smaller this risk but the larger the cost of inspection.
When the incoming lots are of a good quality level, the average quality level of a series of lots will be even better when the rejected lots are screened and resubmitted. The number of nonconforming articles in accepted lots is controlled by the size of the sample and the criteria of acceptance that are placed on the sample.
This standard does not contain the Military Standard’s requirement for tightened inspection when the quality history of a supplier is unsatisfactory. If the standard deviation of the process is not asmt, the standard deviation of the sample is calculated and used. The constant interval is determined by dividing the lot size by the sample size and by rounding the quotient down to the nearest whole number. This quantity may be a shipment from a supplier, articles that are ready for a subsequent manufacturing operation, or articles ready for shipment to a customer.
If one or more of these conditions are not met, a variables plan cannot be used. The plan of Table 4, which is used for destructive testing, is not from the Military Standard. Users of this standard are expressly advised ast determination of the validity of any such patent rights, and the risk of infringement of such rights, are entirely their own responsibility.
The larger the proportion of nonconforming articles in an inspection lot, the more likely it will be that the sample will indicate that the lot is unacceptable. Take the rst two digits in each group of ve digits. If the test method is destructive, the sample size shall be that directed in 8.
If corrective action is taken sstm the supplier so that there is a low asym rate of initially supplied lots, the average quality level will be better than the AOQL Note 1.
Starting at this point, a coin is tossed to decide whether to go up or down the column; heads, up; tails, down. ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this standard.
A method for doing this is described in the following.