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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So the selection of a sampling plan involves the balancing of the costs of inspection against the consequences of accepting an undesirable satm of nonconforming articles.
Using the arithmetic mean of these values, the standard deviation b062 the process, and the factor k that is found in the Tables, a number is calculated see 9. Inspection lots that are unacceptable with respect to one or more requirements shall be astk. The tables give the AOQL for each plan. Sampling plans based on inspection by variables are given in Test Method B Random sampling procedures are given in the Annex of this test method.
You may experience issues viewing this site in Internet Explorer 9, 10 or In accordance with Table 3, a sample of items is to aetm drawn. Also, some test methods are destructive, in which cases sampling inspection must be used to avoid destroying the lot. If every article in an inspection lot conforms to its requirements, every article in the sample will conform also. An alternative is rectifying inspection in which rejected lots are screened and used.
The resubmitted lot shall be inspected only for the characteristics for which it was rejected. Last previous edition approved in as B — 88 The plan of Table 4, which is used for destructive testing, is not from the Military Standard. Astmm the articles are not so mixed, and if it is thought to be impractical to mix them, bias will result if the entire sample is drawn from a single or a few layers. 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 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.
Each article must be tested in the same way for example, coating thickness must be measured at the same location, see X2. Additional plans that may serve these needs are given in Guide B If only a few articles in an inspection lot are nonconforming, the chances are that the sample will indicate that the lot is acceptable; but there is a small chance that the sample will indicate that the lot is unacceptable.
They may be replaced with conforming articles.
ASTM B602 – 88(2016)
In plans of this type, several articles of product are drawn from a production lot. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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. These are explained in Test Method B There may be instances in which tighter or looser plans or ones that are more discriminating are desired.
ASTM B – 88() Standard Test Method for Attribute Sampling of Metallic and Inorganic Coatings
Random numbers may be obtained from books pertaining to statistics. Based on the results, a decision is made either to accept or reject the inspection lot. All other items are then drawn at a constant interval following the rst item. A random number from 1 to 24 is selected either from a table see A1.
Through the use of sampling plans, the risk of error is known and controlled. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. The sample then consists of articles numbered 31, 20, 8, 26, 53, 65, 64, 46, 22, 6, 41, 67, and Link to Active This link will always route to the current Active version of the standard.
The poorest average quality level that can result from the use of a given sampling plan when screening of rejected lots is done is called the Average Outgoing Quality Limit AOQL. Worldwide Standards We can source any standard from anywhere in the world. Signicance and Use 4. There may be instances in which tighter or looser plans or ones that are more discriminating are desired.
Screening is to be used only when required by the purchaser. Such lots will always be accepted. Active view current version of standard.
ASTM B – 90() Standard Test Method of Variables Sampling of Metallic and Inorganic Coatings
Find Similar Items This product falls into the following categories. When incoming lots are of a poor quality level, the average quality of a series of accepted lots will again be good because many of the ast, lots will be rejected and upgraded.
Ashm constant interval is 24 divided by The specific plans selected are identified in Tables 1- 3 of this test method. Additional plans that may serve these needs are given in Guide B These are explained in Test Method B Screening of rejected lots will substantially increase the cost of inspection if the incoming lots are much worse than AQL quality. There is always a risk that a random sample will not describe correctly the characteristics of the lot from which it is drawn, and that an unacceptable lot will be accepted or an acceptable lot will be rejected.
The articles are numbered 1 through 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. Other tests can destroy the coating in nonessential locations, in which case the item can still be functional. Such lots will be 6b02 Note 1.