Accuracy and Application of Threshold Odor Tests

Calculation of Threshold Odor

“…Early work in the field of odor measurement has been discussed by Gamble (2) and Fair (3); more recent developments are presented by Hulbert and Feben (4), Spaulding (5,6) and in the report of the A.W.W.A. Committee on Activated Carbon Research (7).…”

“…Usually the number of samples that may be tested is limited to two or three because of fatigue. Parallel testing has been advocated by Spaulding (5) and Hassler ( 4 ), who have shown that the improvement in the precision of measurement with this procedure is indeed significant. Of course, parallel testing and interpretation of results on a relative basis does not help the operator determine the absolute threshold odor (T.O.)…”

“…Even in such tests, the method usually provides greater precision. An instance of this may be seen in the interesting case recorded by Spaulding ( 5) in which Observer F, who was usually consistent, suffered a temporary period of uncertainty of response and gave an unusual number of anomalous results in contrast to Observer E who turned in a perfect record with no anomalous responses on the same sample. If Observer F's record is calculated by Method D an excellent agreement with Observer E appears, despite the unusual number of anomalous results.…”

“…Method C: The values of n for the three highest dilutions positive (2, 3, 7) are added to the values of n for the three lowest dilutions negative (4,5,6) and the mean 11 computed (4.5). The T.O.…”

“…• 1. Technique: The experimental technique employed was essentially that recommended by Spaulding (5). Some results, however, were obtained using the "one-man" test to be described.…”