- Author
- Mandel, J. | Steel, M. N. | Sharman, L. J.
- Title
- National Bureau of Standards Analysis of the ASTM Interlaboratory Study of DOC/FF 3-71 Flammability of Children's Sleepwear.
- Coporate
- National Bureau of Standards, Washington, DC
- Journal
- ASTM Standardization News, Vol. 1, No. 5, 9-12, May 1973
- Keywords
- FF 3-71 | childrens sleepwear | flammability | test methods | fabrics | statistical analysis | laundering | char length | textiles
- Identifiers
- childrens sleepwear fabrics - pass/fail evaluation; number of laboratories that find conformance and nonconformance; standard error for average char length of five specimens; probability of agreement for two laboratories; probability of agreement for sixteen laboratories
- Abstract
- ASTM Committee D-13 on Textile Materials carried out an interlaboratory study on the test method given in COC/FF 3-71. Standard for the Flammability of Children's Sleepwear. Sixteen Laboratories and eight fabrics were involved. Committee D-13's conclusions were that the study demonstrated that laboratories do not obtain the same "pass-fail" results when testing the same fabrics with DOC/FF 3-71 as written and, in fact, gross differences in reproducibility were obtained. The same test data was analyzed at NBS. The analysis reported in this paper leads to conclusions contrary to those reported by D-13. The NBS report shows theoretically that with a go-no-go test, such as that for children's sleepwear, the probability of complete agreement between laboratories is attained only when the material under test is either so far superior to the test method requirements or so far inferior to them that unavoidable test method fluctuations have no effect on the outcome of the test. For a fabric that is only 2 percent defective, the probability of complete agreement between 16 laboratories is down to 72 percent. The data provide no evidence to support D-13's conclusion that gross differences in reproducibility are obtained.