Citation

Poon R, Hodgson BT, Hinberg I, Rowatt C. J. Can. Soc. Forensic Sci. 1987; 20(1): 19-27.

Copyright

(Copyright © 1987, Canadian Society of Forensic Science, Publisher Informa - Taylor and Francis Group)

DOI

10.1080/00085030.1987.10756938

PMID

unavailable

Abstract

We have designed a breath alcohol simulator and have used it to evaluate the critical performance characteristics of three pocket-size breath alcohol analyzers: the Alco-Sensor III, the Alcohol-Checker RK-1000 and the Breathalyser PMT-1. We also evaluated the accuracy and precision of the analyzers in self-monitoring of breath alcohol concentrations by comparing the results obtained by six volunteer drinkers with Breathalyzer® Model 900A and Intoxilyzer Model 4011AS results. Studies with the simulator showed that Alcohol-Checker and Breathalyser PMT-1 readings were very sensitive to variations in flow rate and duration of air flow (and hence, to variations in volume of breath exhaled). The Alcohol-Checker was also affected by the distance of the sensor from the outlet of the simulator. The Alco-Sensor III was unaffected by these variables. It was the only analyzer found to be sufficiently accurate, precise (CV < 6%) and reliable over the clinically significant range of alcohol concentrations. Linear regression analysis of the results obtained in tests of drinking volunteers showed that Alco-Sensor readings correlated well with those of the Breathalyzer® (r = 0.982), whereas those obtained with the Alcohol-Checker and the Breathalyser PMT-1 correlated poorly (r = 0.086 and--0.127, respectively). The Alco-Sensor had excellent diagnostic sensitivity and specificity at the critical decision level of 0.08 g/dL. The Alcohol-Checker had very poor diagnostic sensitivity but appeared to have very good diagnostic specificity due to the poor analytical sensitivity of the device. As a result, the device either failed to detect the presence of alcohol, or underestimated its concentration. The Breathalyser PMT-1 had poor clinical specificity but did identify 65% of the people who had a blood alcohol concentration of > 0.08 g/dL.