Patent ID: 7095501

Claim:
An ethanol sensing unit located in a passenger compartment of a vehicle, the ethanol sensing unit comprising: means for collecting ethanol vapors within an air sample taken from the passenger compartment while the collecting means is at a first temperature; means for heating the collecting means to a second temperature higher than the first temperature so as to release ethanol vapors from the collecting means; means for delaying operation of the heating means for a predetermined period of time during which the collecting means collects ethanol vapors from the air sample; and means for sensing the ethanol vapors released from the collecting means when heated by the heating means and providing therefrom an output ethanol concentration signal; means for sensing a state of a system of the vehicle that is capable of altering the concentration of vapors in the passenger compartment; and means for modifying the output ethanol concentration signal responsive to the sensed state of the system of a vehicle that is capable of altering the concentration of vapors in the passenger compartment to provide a datum indicative of alcohol impairment of a vehicle driver in the passenger compartment.