• Stephen Biss

What happens to ambient fail system if ambient conditions change gradually?

Let's suppose that we have an Intoxilyzer approved instrument (in this case an Intoxilyzer 5000) in a police breath room where ambient conditions are changing all the time (e.g. the room was painted, some standard alcohol solution was spilled, the police officer wiped her boots on a paper towel on the floor, a heavily intoxicated person was recently in the room). The changing ambient conditions in our scenario may include either ethanol (drinking alcohol) or an interferent such as a hand cleaner.

IR evidentiary breath instruments always need a zero starting point. The ambient fail flagging system triggers at about 19 mg / 100 mls on an Intoxilyzer 5000 or 5000C and at about 10 mg / 100 mls on an Intoxilyzer 8000 or 8000C. The set point may vary by state or province.

The problem is that the 19 or 10 mg/ 100 mls threshold assumes an accurate zero. But changing conditions, as simulated in this experiment, may produce numerical results on the instrument screen and the test record that have no meaning in reality without triggering an ambient fail.

#ambientfail #truezero

16 views0 comments

© 2020 Allbiss Lawdata Ltd. All rights reserved. This is not a government web site.



For more information respecting this database or to report misuse contact: Allbiss Lawdata Ltd., 303-470 Hensall Circle, Mississauga, Ontario, Canada, L5A 3V4, 905-273-3322. The author and the participants make no representation or warranty  whatsoever as to the authenticity and reliability of the information contained herein.  WARNING: All information contained herein is provided  for the purpose of discussion and peer review only and should not be construed as formal legal advice. The authors disclaim any and all liability resulting from reliance upon such information. You are strongly encouraged to seek professional legal advice before relying upon any of the information contained herein. Legal advice should be sought directly from a properly retained lawyer or attorney. 

WARNING: Please do not attempt to use any text, image, or video that you see on this site in Court. These comments, images, and videos are NOT EVIDENCE. The Courts will need to hear evidence from a properly qualified expert. The author is not a scientist. The author is not an expert. These pages exist to promote discussion among defence lawyers.


Intoxilyzer®  is a registered trademark of CMI, Inc. The Intoxilyzer® 5000C is an "approved instrument" in Canada.
Breathalyzer® is a registered trademark of Draeger Safety, Inc., Breathalyzer Division. The owner of the trademark is Robert F. Borkenstein and Draeger Safety, Inc. has leased the exclusive rights of use from him. The Breathalyzer® 900 and Breathalyzer® 900A were "approved instruments" in Canada.
DrugTest® 5000 is also a registered trademark of Draeger Safety, Inc.. DrugTest® 5000 is "approved drug screening equipment" in Canada.
Alcotest® is a registered trademark of Draeger Safety, Inc. The Alcotest® 7410 GLC and 6810 are each an "approved screening device" in Canada.
Datamaster®  is a registered trademark of National Patent Analytical Systems, Inc.  The BAC Datamaster® C  is an "approved instrument" in Canada.