NCJ Number
113303
Journal
Forensic Science International Volume: 37 Issue: 3 Dated: (May 1988) Pages: 205-213
Date Published
1988
Length
9 pages
Annotation
Duplicate breath alcohol testing from each individual provides confidence in the results when reasonable agreement (i.e. + 0.02 g/210L) is achieved.
Abstract
For this reason many jurisdictions required duplicate testing. The State of Washington has recently implemented an infrared breath testing program and now requires two breath samples from each individual. Statistical analysis of 1847 duplicate breath tests is presented. Three variables are analyzed: first alcohol result (ALC1), the absolute difference between the two breath samples (DIFFA), and the signed difference between the two breath samples (DIFFS). The first breath alcohol result ranged from 0.02 to 0.338 g/210 L with a mean of 0.157 g/210 L. The absolute difference ranged from 0.00 to 0.05 g/210 L. The signed difference ranged from -0.05 g/210 L to 0.05 g/210 L. The absolute difference was regressed upon the first alcohol result and resulted in poor correlation of r = 0.212. Duplicate breath test differences do not appear to be a function of subject's alcohol level, but rather of sample provision. (Publisher abstract)