Barry Knott, Breathalyzer Test Expert

Barry KnotBarry R. Knott is currently the president of Lifeloc Technologies, Inc., a company that manufactures breath alcohol testers for law enforcement, transportation, education and the workplace. He is also general manager of the Lifeguard Consumer Division, which is a unit of Lifeloc that manufactures precision feul cell testsers for consumers. His background includes senior marketing, general management and president positions in the technology and breath alcohol testing industries.

How does a breathalyzer device work?
There are two technologies commonly used in breath alcohol testing: fuel cell and semiconductor.

Fuel cell breathalyzers are the ‘gold standard’ of hand-held alcohol testers for both personal and professional use. They are the choice of professional users such as law enforcement and serious personal users such as concerned parents and individuals who require measurement accuracy they can trust.

In fuel cell instruments, the breath is directed into a fuel cell with dual platinum electrodes where it is oxidized and generates electrical current. The higher the alcohol content of the breath, the greater the current output of the fuel cell. By precisely measuring the current produced in the fuel cell, an accurate measure of breath alcohol content (BAC) is recorded.

How accurate are breathalyzer tests?
Lifeloc platinum fuel cell technology, in combination with the advanced measurement algorithms that we use in our professional units and in the LifeGuardTM personal breath tester, are extremely accurate and very reliable. Unlike semiconductor devices, our fuel cell technology reacts only to alcohol and not to other airborne substances such as gasoline, cigarette smoke, acetones and ketones. Contrary to popular myths, a precision fuel cell tester cannot be fooled by inhaling instead of blowing, pennies in the mouth, gum or breath mints.

In alcohol testers, you get what you pay for. Semiconductor testers, while inexpensive, are not to be trusted. These testers can give positive alcohol readings even when no alcohol is present. Semiconductor testers require frequent re-calibration and have a short working life. Independent scientific testing has repeatedly found a wide variation in alcohol readings produced by the leading semiconductor devices when tested against a known alcohol concentration.

Are there any significant differences between the breathalyzer devices that law enforcers use versus the devices for sale to consumers?

Law enforcement breath testing is serious and important work requiring instruments of high precision and reliability. Fuel cell, rather than semiconductor technology, is used. LE units are rigorously tested and maintained to very high standards, and they are tested and approved to evidential standards by the Department of Transportation, as well as approved by each state.

Consumer breathalyzers must be cleared by the FDA to be legally sold in the US. The FDA does not require that consumer breath testers meet the same standards of accuracy and precision as required by law enforcement. This has allowed the proliferation of cheap and unreliable imports that probably do more harm than good.

What are some advantages to a consumer owning a personal breathalyzer?
Only a precision breath tester can provide an accurate measure of BAC at any point in time. Other techniques such as "drink tables" and "drink software" may be education but they are not reliable measurement tools. Only a good breathalyzer can account for the many variables affecting individual alcohol intoxication, such as sex, age, percent body fat, health and how much alcohol was in the drink.

Useful consumer applications include:

  • Home bar and party use
  • Self-testing
  • Morning after testing
  • Office and holiday party safety
  • Parental testing and education
  • Responsible recreational vehicle use

What advice can you give to people who wish to purchase their own breathalyzer?

  • Do not expect accuracy, reliability or long life from semiconductor devices.
  • Insist on platinum fuel cell technology and FDA-approved products.
  • Check the country of manufacture. With imports, consumers have little recourse if the unit needs repair.
  • Beware of marketing claims.
  • Do not drink and drive.

For more on breathalyzer tests, read our Breathalyzer Test Guide. To find a breathalyzer, visit our Breathalyzer Test Directory.

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