Here, from the collection of the museum, is a Smith and Wesson Breathalyzer Model 900 which was used by Minneapolis Police Officers in the 1970s and 1980s.
We visited with Retired Officer J. J. John and Retired Officer Larry Wilkens to learn more about how the Breathalyzer 900 operated.
The Breathalyzer 900 used a chemical contained within two ampoules to measure a subject’s blood alcohol level. The driver would blow into a tube attached to the machine, which mixed the breath sample with the chemical.
The resulting reaction enabled the Breathalyzer to determine the alcohol content of the driver’s breath, which it then converted to the blood-alcohol level.
The machine then transferred the results of the subject’s test to a read-out card.
Both officers reported that the machine was simple to operate.
Many thanks to Retired Minneapolis Police Officers J. J. John and Larry Wilkens for providing context for this article