Breath Tests

When someone blows into a breath-test bag, any alcohol in his breath is turned into acetic acid (vinegar), changing the color of the crystals in the blowing tube. The more crystals that change color, the more alcohol is in the body. The first breath-alcohol test was developed by an American doctor, Rolla N. Harger, who called it a "drunkometer." The breath-alcohol tests used by the police today, however, are usually electronic, and much more accurate than the inflatable plastic bag type. They use the alcohol blown in through the tube as fuel to produce electric current. The more alcohol the breath contains, the stronger the current. If it lights up a green light, the driver is below the legal limit and has passed the test. An amber light means the alcohol level is near the limit, a red light is above the limit, and in both cases the driver has failed the breath test and needs further testing. These tests are used to judge a driver's ability to drive. A high intake of alcohol dulls the nervous system and slows up coordination. The best advice concerning these are the familiar "If you drink, don't drive; if you drive, don't drink!"