Breath Technology

When it comes to measuring a person’s blood alcohol concentration, most Americans are familiar with punitive breathalyzers that require drivers to blow into a tube or other sensor. In contrast, the breath system being developed by the DADSS Program is designed to passively and unobtrusively analyze alcohol in a driver’s breath, so drivers can simply enter the vehicle and breathe as they normally would. The sensor is being developed by Senseair, a leading global provider of air and gas sensing technology.

How It Works

The system is being designed to draw the driver’s exhaled breath into a sensor, which measures the concentrations of alcohol and carbon dioxide present. The known quantity of carbon dioxide in human breath serves as an indicator of the degree of dilution of the alcohol concentration in exhaled air.

Molecules of alcohol and those of tracers such as carbon dioxide absorb infrared light at specific wavelengths. The device is being designed to direct infrared light beams on the breath sample and analyze the wavelengths returned to quickly and accurately calculate the alcohol concentration. The device is designed to be highly sensitive in order to analyze diluted breath samples at dilutions expected from a driver’s natural breath plume. Program engineers continue to work with Senseair to evolve the technology by utilizing mirrors to reduce the required optical length of the device so that it can seamlessly fit into vehicles. 

Testing The Prototype

To test the devices under development, the DADSS Program has developed a wet gas breath simulator. The simulator blends gases such as carbon dioxide, nitrogen and oxygen with moisture to create an “exhaled breath” that matches the composition, temperature and pressure of a natural human breath. Ethanol can then be added to the breath at various concentrations. Today, the Senseair device continues to run through a series of human subject tests, as well as durability tests in different environmental situations, from temperature shifts, to sudden changes in motion, to interference such as dust or mechanical shock.

About The Manufacturer

Senseair is an innovation-based sensor company and leading manufacturer of infrared carbon dioxide sensors and controllers. It is based in Sweden, with over 20 years’ experience in the field of infrared gas measurement technology. Learn more about the manufacturer at: