Pot smokers have achieved an equality of sorts with alcohol drinkers: a new "breathalyser" test designed to catch motorists under the influence of marijuana.

The device is about the size of a cigarette holder and works the same way as the alcohol "breathalyser" test. Both the "drunk test" and the new "funk test" use a breath sample taken at the roadside, quickly analyzed with a kit back at the police station. The device is being tested by the California Highway Patrol on test-driving courses. Drivers are being given different doses of marijuana, then tested for their driving reactions, according to Dr. Emory Zimmerman at UCLA, one of four researchers who developed the testing system. The kit can detect marijuana intoxication up to about two hours after the last drag on a cigarette, Zimmerman said. The device absorbs the chemical intoxicant in marijunana, tetrahydrocannabinol (THC), into the lining of a three-inch tube. Later, the lining is soaked in a solution containing radioactive molecules which attach themselves to the THC molecules. With the two molecules stuck together, they can be counted on a machine like a geiger counter. The kits may be ready for police use within a year or two, depending on how quickly state legislatures can adopt the necessary laws to make the ir use legal. Most state laws now for bid driving while intoxicated, without discriminating between alcohol and drugs; police and researchers now must show the link between the tested breath levels of THC and deteriorating physical performance in a car. Zimmerman said that the kit can detect a level of 5 nanograms (a nonogram is a billionth of a gram) of THC per milliliter of blood, the level at which intoxication begins. He said one joint of marijuana can produce levels of 30 to 50 nanograms on the same scale, a level of intoxication that lasts up to two hours.