Portable Alcohol Detection System with Breath-Recognition Function

We have developed a portable device that uses a non-contact breath sensor to detect breath-based alcohol. The device's sensor detects saturated water vapor in human breath, and three semiconductor gas sensors detect ethanol, acetaldehyde, and hydrogen. The device can determine whether the gas introduced into it is human breath and the alcohol level at the same time. This ensures that the sample is of a person's breath, not from an artificial source. Alcohol concentration is calculated using an algorithm based on a differential evolution method and each gas sensor's output. The developed device exhibited a measurement accuracy of approximately ±10 ppm by exhaled breath.