Citation

Schmidt U, Jachau K, Wittig H, Bartels H, Krause D. Blutalkohol 2000; 37(2): 92-100.

Affiliation

stitut fur Rechtsmedizin, Otto-von-Guericke-Univ. Magdeburg, 39120 Magdeburg, Germany.

Copyright

(Copyright © 2000, International Committee on Alcohol, Drugs and Traffic Safety and Bund gegen Alkohol und Drogen im Straßenverkehr, Publisher Steintor Verlag)

DOI

unavailable

PMID

unavailable

Abstract

The breathalyser Alcotest Evidential 7110 MK III which was approved and calibrated by the PTB in Braunschweig was used to simultaneously measure 454 blood alcohol and breath alcohol concentrations in drinking experiments as well as in test carried out under restaurant conditions. The 588 measuring records resulting from this test were made available for evaluation. Approximately every eighth record (12.4%) revealed an error that caused a premature termination of the measuring process. The most frequent errors were 'alcohol in ambient air' and 'difference between individual values'. This error rate was about 25% under restaurant conditions whereas in individual tests in lab conditions it amounted to around 10%. In addition, 5.2% of all records, i. e. every twentieth data print, contained error messages where, although there was no interruption of the measuring process, a valid reading could only be obtained after the repetition of the test. Hence, the overall error rate estimated to be about 17% under test conditions. It can be assumed that this value is even higher in police practice. Short-chain alcohols can also set off the error message 'alcohol in ambient air', as can ether and chloroform. The examined household chemicals (cleaning agents, paints adhesives etc.) did not exert any interfering influence provided that they did not contain any of the above mentioned alcohols. The error message 'alcohol in ambient air' was also caused by cosmetics containing alcohol. In the case of 1 ml of perfume being applied onto cellulose the error message was caused up to 30 minutes after application. 'Residual alcohol in the mouth' regularly came up after rinsing the mouth with alcoholic beverages, semi-luxury goods containing alcohol or mouthwashes. Other tested foods and semi-luxury foods did not influence the readings. As a whole, the breathalyser is a reliable device for measuring breath alcohol concentration in theory and practice. Its sensitivity to other substances leads to a relatively high frequency of error messages. In practice, an error free measurement should take about 15 minutes.