It might be interesting to note that the first Breathalyzer for testing alcohol levels was invented in 1954.  The first instrument for testing was called The Drunkometer, but calibration was an issue as it was moved about so the new Breathalyzer’s portability was a big improvement.  The breathalyzer estimates blood alcohol content from a breath sample taken and can not determine exact levels without a blood test.  Although Breathalyzer has become a term that came from the first brand by that name they are sold under many other names.