Laser device can detect alcohol in cars

Researchers have developed a laser device that can detect the presence of alcohol vapours inside a moving car.
The laser system, developed at the Military University of Technology in Warsaw, is set up on the side of the road to monitor each car that passes by.
If alcohol vapours are detected in the car, a message with a photo of the car including its number plate is sent to a police officer waiting down the road.
Then, the police officer stops the car and checks for signs of alcohol using conventional tests.
Researchers noted that the device would likely also identify cars where the driver is sober but the passengers are not, or if there is spilled alcohol in the car, and it "will surely decrease the number of cars that have to be checked by police and, at the same time, will increase efficacy of stopping drunken drivers."

Researchers Jaroslaw Mlynczak, Jan Kubicki, and Krzysztof Kopczynski at the university's Institute of Optoelectronics tested the device with a car deployed on the road while the laser stayed in the laboratory next to an open window, making it possible to extensively monitor the device.

The researchers simulated alcohol vapour coming from a human lung by evaporating a water solution of alcohol of an appropriate concentration and at an appropriate temperature.
The results showed that the presence of alcohol vapours was detected at concentrations of 0.1 per cent and greater.
"From the practical point of view, there seem to be some countermeasures, such as driving with windows open, solar screens on the side windows, etc, that can be applied by drivers to deceive the system," the authors wrote in the Journal of Applied Remote Sensing.

"However, such situations are very easily detected by the system, which sends this information to the policeman indicating that the car should be checked," the authors said.