• Stephen Biss

Can a cell phone transmission cause a false breath reading?

In this experiment a Nokia cell phone was transmitting close to an Intoxilyzer® 5000 evidentiary breath testing instrument. The subject who had a true BAC of 000 blew 10, 34, and 33 mg / 100 mls, all results in good agreement (within 20 mg /100 mls of each other truncated).

Cell phones should not be used in a police station breath room because they can cause RFI interference to the breath analysis without triggering the RFI detection system on the evidentiary breath equipment. Just because an instrument does not flag "RFI Inhibit" or a similar warning does not prove there was no dangerous RFI in the room.

Cell phones can produce false or exaggerated readings during both subject tests and calibration checks. They also should not be used during diagnostics, reference checks, or air blanks.

Cell phone RFI can also cause bizarre other effects such as false error messages of invalid sample, range exceeded, unstable reference, and ambient fail.


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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.