Radio Frequency Interference messages during breath testing of suspected impaired drivers using the Intoxilyzer® 5000C: A 13-year retrospective analysis

In order to address concerns on the hypothetical impact of Radio Frequency Interference (RFI) on breath alcohol testing, retrospective analysis of the incidence of RFI exception messages obtained during testing of suspected impaired drivers on the Intoxilyzer® 5000C over a 13-year period (1997 to 2009) was examined. Occurring in less than 0.48% (n=128) of the 26,939 drivers tested, RFI messages were rare. Even more infrequent were multiple RFI messages, which occurred in only 10.2% of RFI-positive cases (n=13). The incidence of RFI messages attributable to a particular testing location (p=0.98), a specific instrument (p=0.98), or year of testing (p=0.99) showed no significant effect. Additionally, no evidence is shown by the data that, in addition to those already detected by the instrument, hypothetical "undetected" RFI events affected either the calibration check results or the subject breath tests in this study. In order to protect the internal electronics against RFI, instruments are designed with an RFI detection system and shielding. Serving as an additional safeguard against "undetected" RFI impacting the tests, as well as to increase the scientific confidence in the results obtained, the breath testing procedure requires two tests in good agreement (within 20 mg/100 mL truncated).

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  • English

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  • Accession Number: 01613671
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Oct 21 2016 4:32PM