Active Standard ASTM D2525 | Developed by Subcommittee: D13.13
Book of Standards Volume: 07.01
Historical (view previous versions of standard)
Significance and Use
5.1 This recommended practice furnishes directions for the sampling of wool of the various forms indicated in Section 1, in order that correct probability statements may be made about the relationship between the sample mean and the population mean. If these statements are to be correct, certain conditions, which are stated, must hold.
5.2 This recommended practice requires that a deliberate act of randomization be performed so that all potential sampling units have approximately the same chance of being taken and no sampling unit is deprived of its chance of being taken.
5.3 In any case where insufficient information about the variability of the sampling units within the lot is available, directions are given for calculating confidence limits for the sample mean so that a correct probability statement can still be made.
1.1 This practice covers the design of a sampling plan to be used to obtain samples for the determination of the moisture content of grease wool, scoured wool, carded wool, garnetted wool, wool top and intermediate products, and rovings.
1.2 Directions are given for the designation of sampling units, calculation of the number of sampling units required to achieve a preselected precision and confidence level or, alternatively, for calculating the confidence limits for the mean based on the variability of the sample tested.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
D123 Terminology Relating to Textiles
D1060 Practice for Core Sampling of Raw Wool in Packages for Determination of Percentage of Clean Wool Fiber Present
D1576 Test Method for Moisture in Wool by Oven-Drying
D2462 Test Method for Moisture in Wool by Distillation With Toluene
E122 Practice for Calculating Sample Size to Estimate, With Specified Precision, the Average for a Characteristic of a Lot or Process
ICS Number Code 59.060.10 (Natural fibres)