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The Draeger Alcotest 9510 Breath Machines Are Here!

Posted Thursday, August 23, 2018 by Andrew Charles Huff

Washington State recently rolled out the new breath test machine to be used in DUI cases called the Alcotest 9510, manufactured by a German company called Dräger Industries. The Washington State Patrol replaced its aging fleet of DataMaster and DataMaster CDM breath test machines which have been in service since 1984.

The Alcotest 9510 measures a DUI suspect’s breath alcohol content by actually taking two separate breath samples from each suspect, then sending those samples one at a time through the machine’s two testing chambers. The first chamber analyzes alcohol contained in the breath sample by using a chemical reaction from an electrochemical cell (referred to as the EC result). Next the machine sends the same breath sample into a second chamber where it is tested using infrared lights called infrared spectroscopy (referred to as the IR result). Once IR result is completed the machine purges itself of the air sample and gets ready for the second breath sample from the suspect. The result is actually four readings – 2 EC results and 2 IR results.

For the machine to provide a successful final BAC result, all four readings must be within a certain tolerance of one another to be considered a “true” reading. This is done by plugging the numbers into an algorithm created by the manufacturer. However, Washington State Law gives the defendant the benefit of the doubt by taking the lowest of the 4 readings and rounding down to the second decimal place.

Additional breath testing requirements to receive an acceptable breath sample include minimum air volume and blowing duration. So if the air sample is too small the machine cannot test it.

Also, the mouth piece must be changed between each breath to minimize the effects of any residual alcohol. There must also be a two-minute lock out between each breath sample to ensure the machine has enough time to purge the last breath sample before taking a new one.

The police officer must also observe the suspect for 15 minutes prior to blowing into the machine as well making sure all radio devices, including cell phones are removed from the testing room.

Call my office for more information on the Alcotest 9510 or other questions you might have.