NCJ Number
77025
Journal
Canadian Society of Forensic Science Volume: 14 Issue: 1 Dated: (March 1981) Pages: 1-13
Date Published
1981
Length
13 pages
Annotation
The accuracy of the Standard Alcohol Solution (S.A.S.) test for determining the correctness of readings from the Borkenstein Breathalyzer is examined.
Abstract
The S.A.S. test is conducted to check the accuracy of this evidentiary breath testing instrument each time a person's breath is analyzed. The study compared the expected readings listed in the Breathalyzer instruction manual with those predicted from data in the scientific literature and determined the effect of a room-solution temperature differential on the accuracy of the test. The results of a statistical treatment of the data relating the distribution of alcohol between air and water to the temperature for dilute aqueous ethanol solutions show that the two are not linearly related, in spite of recent reports. Tests using an equilibrator and an aqueous alcohol solution indicate that higher than expected results will be obtained on a Breathalyzer if the ambient temperature is higher than the solution temperature is lower than the solution temperature. Maximum differences were minus 16 mg per 100 ml when ambient temperature was 10.6 degrees centigrade cooler than the solution and 12 mg per 100 mL when the ambient temperature was 9.9 degrees warmer. Condensation was present in the outlet tube of the equilibrator during all tests where the solution was warmer than the room. A figure, data tables, a French summary, and a 17-item reference list are included.