Breathalyzer® Tests with the Equilibrator and the Effect of room Temperature

Abstract

Statistical treatment of the data relating ka/w to temperature for dilute aqueous ethanol solutions suggests that 1n ka/w is not linearly related to temperature as has recently been reported. The relationship:yields calculated values of ka/w that fall within ± 1 x 10-6 of the experimental range (T in QC).Tests utilizing an equilibrator and an aqueous alcohol solution (3.41 mg/mL) indicate that higher than expected results will be obtained on a Borkenstein Breathalyzer if the ambient temperature is higher than Jhe solution temperature and lower results will be obtained if the ambient temperature is lower than the solution temperature. Maximum differences were -16 mg/100 mL when ambient temperature was 10.6 Q C cooler than the solution and 12 mg/100 mL when ambient temperature was 9.9°C warmer than the solution. Condensation was present in the outlet tube of the equilibrator during all tests where the solution was warmer than the room (N-36). RESUME Le traitement statistique des donees rapportant ka/w a la temperature des solutions aqueuses d'alcool ethylique semble indiquer que 1n ka/w =0.0000326 e(0.0840T -0.000318 T2) donne des valeurs calculees de ka/w etant de ± 1 x 10-6 de I'intervalle experimental (T en QC).Les tests qui font appel a un equilibreur et a une solution aqueuse d'alcool (3.41 mg/mL) indiquent que des resultats plus eleves que prevus seront obtenus avec le Borkenstein Breathalyzer® si la temperature ambiante est plus elevee que la temperature de la solution, alors que des resultats moins eleves seront obtenus si la temperature ambiante est plus basse que la temperature de la solution. Les differences maximales furent -16 mg/100 mL quand la temperature ambiante etait 10.6 Q C plUS froide que la solution, et 12 mg/100 mL quand la temperature ambiante etait 9.9 Q C plus chaude que la solution. 11 y avait de la condensation dans le tube de sortie de I'equilibreur dans tous les tests oil la solution etait plus chaude que la temperature de la piece (N-36).

A Simulation of the Effect of Blood in the Mouth on Breath Alcohol Concentrations of Drinking Subjects

“…< 0.01Og/21OL). The accuracy of the Breathalyzer was then checked using Alcohol Standard in an equilibrator (13). The Alcohol Standard solution was manufactured at the Centre of Forensic Sciences and tested by the modified Widmark method (14) to ensure that the concentration was 3.38 ± 0.07 milligrams of alcohol in one millilitre of solution (mg/mL) as recommended by the Alcohol Test Committee (15).…”