The CO Check Pro has been designed for the healthcare professional to carry out simple breath tests whilst providing comprehensive results. From a single breath the results are instantly displayed in PPM and %COHb coupled with an appropriate coloured visual effect to see if the person is a non-smoker, light smoker, smoker or heavy smoker. It is widely accepted and acknowledged a non smoker will perform a test and will display a level of 6ppm or less. A light smoker will perform a test and have a reading between 7 ? 10ppm. A smoker will perform a test and have a reading of between 10 ? 20ppm and a heavy smoker will display a reading of 20ppm or more.