Citation

Slemeyer A. Blutalkohol 2001; 38(1): 1-6.

Affiliation

FH Giessen-Friedberg, Fachbereich Elektrotechnik 1, D-35390 Giessen, Germany.

Copyright

(Copyright © 2001, International Committee on Alcohol, Drugs and Traffic Safety and Bund gegen Alkohol und Drogen im Straßenverkehr, Publisher Steintor Verlag)

DOI

unavailable

PMID

unavailable

Abstract

Wet bath simulators have been in use for more than 4 decades for calibrating breath alcohol analyzers as they deliver a gas sample similar to human breath with regard to temperature and relative humidity. As the alcohol concentration in the liquid is depleted due to evaporation losses the solution has to be changed after a certain number of tests. This restricted their use in automated calibration systems. The paper describes the design principle of a new wet bath simulator system that offers a long-Term stable output concentration at a defined temperature. To compensate the evaporation losses of ethanol in the liquid phase a certain amount of the simulator solution is replaced. The amount of fresh solution supplied after each test is depending on the volume of generated gas. The Drager ALCOCAL calibrator is the first instrument based on this technique. It has been approved by the German National Institute of Standards (PTB) in Braunschweig. Linking the ALCOCAL unit to a PC provides an automated operation which is very useful for production or calibration services. The paper reports also on results from tests with the ALCOCAL.