BREATH ALCOHOL SIMULATORS WITH ALCOHOL SOLUTIONS IN SEPARATED CHAMBERS

A customary method of simulating breath alcohol is bubbling air through an aqueous alcohol solution of proper concentration at 34 deg C. The decrease of the alcohol concentration of the solution and hence of the test gas has been calculated as a function of the air throughput. In simulators with one chamber the alcohol concentration decreases exponentially from the initial value. There is also an uncertainty whether the alcohol concentration in the air is in equilibrium with the alcohol concentration of the solution. Improved accuracy is achieved by dividing the solution between two chambers and connecting the gas outlet of the first chamber to the gas inlet of the second. The calculated decrease of the alcohol concentration of the test gas is considerably less than for one chamber up to high air throughput volume. The decrease might be less than 6% when performing 100 tests with the A.L.E.R.T. alcohol screening tester using 2 x 250 ml alcohol solution. The calculated decrease has been checked experimentally, using a precise infrared breath alcohol testing device (the Drager Alcytron). The experimental values agree well with the calculation. Dividing the alcohol solution among more than two chambers leads to even improved long-term stability of the test gas alcohol concentration up to a critical air throughput volume. At higher throughput volumes the alcohol concentration will quickly drop to lower values. In practical use the two-chamber simulator is the best compromise between the accuracy and stability of the test gas alcohol concentration and the ease of handling and price.

• Supplemental Notes:
  • Roadside Surveys--Proceedings of the Satellite Conference to the 8th International Conference on Alcohol, Drugs and Traffic Safety 23-25 June 1980, Umea, Sweden held in association with the International Committee on Alcohol, Drugs and Traffic Safety and organised by the Department of Forensic Medicine, Umea University, Umea.
• Corporate Authors:

  Dokumentationscentralen foer Alkohol- Och

  Narkotikaforskning, CAN, P.O. Box 27302
  Stockholm,   Sweden 
• Authors:
  • Schmidt, M
  • Hattendorff, H-D
• Conference:
  • Roadside Surveys--Proceedings of the Satellite Conference to the 8th International Conference on Alcohol, Drugs and Traffic Safety held in association with the International Committee on Alcohol, Drugs and Traffic Safety and
  • Location: Umea , Sweden
  • Date: 1980-6-23 to 1980-6-25
• Publication Date: 1982

Media Info

• Features: Figures;
• Pagination: p. 179-185

Subject/Index Terms

• TRT Terms: Alcohol breath tests; Alcohols; Blood alcohol levels; Simulation; Test procedures; Testing equipment; Training simulators
• Subject Areas: Safety and Human Factors;

Filing Info

• Accession Number: 00396592
• Record Type: Publication
• Source Agency: National Highway Traffic Safety Administration
• Report/Paper Numbers: HS-037 595
• Files: HSL, USDOT
• Created Date: Aug 31 1985 12:00AM