Alcohol Depletion in Simulator Solutions Used With the Intoxilyzer 5000C System Calibration Check

• NCJ Number: 200577
• Journal: Canadian Society of Forensic Science Volume: 36 Issue: 1 Dated: March 2003 Pages: 11-18
• Author(s): G. A. Kampman
• Date Published: March 2003
• Length: 8 pages
• Publication Format: Article
• Publication Type: Report (Study/Research)
• Language: French; English
• Country: Canada

Annotation

This study evaluated the extent of alcohol depletion that occurred in simulator solutions used in performing repeated calibration checking of an Intoxilyzer 5000C instrument operated in recirculation mode.

Abstract

Using alcohol-water solutions in wet bath simulators for calibration verification of breath alcohol testing instruments is a commonly used safeguard in breath test programs. The forensic value of this practice is critically dependent on the simulator solution maintaining a correct alcohol concentration over the time it is applied for this purpose. Alcohol depletion is a recognized condition with simulator solution use. In order to investigate alcohol depletion in simulator solutions used for repeated calibration checks of Intoxilyzer 5000C instruments operated in recirculating mode, a series of trials were designed to emulate real-life field testing by running repeated system calibration checks over periods that ranged from 14 to 33 days. The first pair of trials used 2 Intoxilyzer instruments and 2 simulators, evaluated alcohol depletion in simulator solutions used for 100 calibration checks performed over 14-day (Trial A and 28-day (Trial B) periods. The second pair of trials used the same design as the first but with 50 calibration checks performed over 33-day periods using another 2 Intoxilyzer instruments (Trials C and D). In three of the four trials, alcohol depletion was found to be significant at the 99 percent Confidence Interval, with solution concentrations decreasing more than 3 percent from the original target values. The use of recirculation for calibration checks of the Intoxilyzer 5000C provided a conserving effect on the amount of alcohol lost from the solution; however, study results suggest that even with recirculation, significant decreases in alcohol concentration occur when repeated tests are performed over time with the same solution. When recirculation is used, alcohol depletion apparently remains a factor that should be monitored as one part of maintaining overall quality in a breath alcohol program. 2 tables, 1 figure, and 8 references