If you go soft on cannabis the police have no check on people driving under its influence. And they will do it - they're doing it now. Dr Parsons said he could see breath analysis for cannabis becoming part of standard random breath testing. The heart of the cannabis breath test device is a sensor disc, the exact chemical composition of which is a secret shared only by Drs Parsons and Mejglo. When an affected driver blows into a mouthpiece chemicals detecting cannabis turn the sensor disc red.
Light hits the disc, is reflected and measured by a photo diode.
With any colour in it, the disc will show proportionately less light and provide a reading. Dr Parsons said the device now represented a prototype, which a manufacturing company could look at and turn into a workable unit. He said progress had been hampered by lack of research funds, particularly in view of cutbacks in Federal Government research funding. If we had received funding we would have had the device out on the streets by now. He said he believed it should now be possible to take a saliva swab from drivers who had breath tested positive to cannabis to test for other drugs, including amphetamines, heroin, or ecstasy.