Standard Practice for Sampling of Plastics
|Publication Date:||10 January 1968|
This practice is primarily a statement of principles to guide purchasers of plastic materials purchased under specifications to prepare sampling plans that will describe sampling procedures and that will enable them to determine within practical limits whether or not the products meet the specifications.
The same principles may be used to guide the preparation of specifications in quantitative terms.
Some of the same principles may be used to determine the actual quality of a product, including its average and variation above and below that average, with respect to a particular property.
Since the design of probability sampling depends upon the ultimate use of the samples and the resulting data, consideration must be given to the intended inspection of the samples. Hence, the design of plans for examination and testing of samples for both their attributes and their variables is included.
This practice is intended for general guidance when little information is available on the variability of the material and of the method of inspection. In some cases, quality control chart methods may be substituted for the procedures herein. In any event, a statistician should be consulted if difficulty is encountered in applying the recommendations herein to the design of a specific sampling problem.
There is no intent to guide the disposition of material that is found to be off-specification by sampling and inspection; disposition is a contractual matter.
The values stated in SI units are to be regarded as the standard.
This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety problems associated with its use. 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.