The comparability of two commonly used carbon monoxide analysis systems: a technical note.

Carbon monoxide (CO) in expired breath is a common strategy for verifying smoking abstinence. The purpose of this investigation was to determine the comparability of two carbon monoxide (CO) analyzers: the commonly used Ecolyzer Series 2000 analyzer versus the new, highly portable, and less expensive Ecolyzer Model 210. Fifty-eight CO readings were obtained from 29 subjects (17 smokers, 12 nonsmokers) and analyzed on both systems simultaneously. Results indicated that the analyzers yielded highly comparable values for both smokers and nonsmokers. Moreover, the correlation between the two units' readings was very high (r = .92, p less than .001). There was, however, a significant analyzer by sex interaction with the Series 2000 analyzer yielding higher values for males. Overall, it was concluded that the Series 210 analyzer is a highly accurate and cost-effective instrument.