deolah

Hi, My final year project is titled as above. i found out i would need a semiconductor alcohol sensor for this project. This as i found out, lcomes in form of chips. i really need to know which one to get for my project to work fine. the Breath alcohol tester is supposed to test the level of alcohol in the breath ( and also blood) of an intending driver. if the BAC is found too high, then it wont allow the car start. Am thinking there should be a relay connected to this device, then to a switch that will operate the car ignition system. Pls give me ideas of the type of semiconductor alcohol microchip sensor to use and how do i get it? do ui have to order for it from my country or i can easily access it? i also need to know the principle of operation of this sensor and howi can calibrate my device to measure different levels of alcohol content. Pls reply asap as my project initiation is dependent on this. thanks a lot.