Section 76 Slope Detector Does Not Always Work

• Library: DWI Experts and the Science of Chemical Tests 2014

Mouth alcohol can cause serious problems for breath testing, partly because the mechanism, called a slope detector, that is installed in the software of the Intoxilyzer 5000 and the BAC DataMaster does not always work. See Patrick Harding et al., The Effect of Dentures and Denture Adhesives on Mouth Alcohol Retention,37 J. FORENSIC SCI. 999 (1992). It is the opinion of the author of this chapter that slope detectors, designed to detect mouth alcohol, do not work.

The problem is simple—the “slope detector,” or “mouth alcohol detector,” is only found when a machine that has IR technology cannot differentiate between alcohol from the lungs and alcohol from a contamination source from food particles, tobacco, GERD, etc. Because the breath test is dependent on an exhalation from the mouth, all sources of alcohol will be...