I have seen all sorts of ways to detect alcohol using NIRS (Near InfraRed Spectrscopy) or FTIR, but they are all quite complicated in that they are using and analyzing a very wide spectrum. In addition, it is not clear as to the environment of where the alcohol is measured in. Some presentations are talking about measuring the
OH-stretch of the
RO-H in the region of
Some related, but not very helpful questions are:
- O-H infrared band dependence of alcohol concentration in water
- These there is this book section which mentions various problems of published spectrum.
Is there a cheaper and more simple way to do this detection, using off-the-shelf components, like IR lasers or diodes?
- I suppose "cheaper" would mean to use just one or very few frequencies, so that one doesn't have to analyze an entire spectrum.
- What are these frequencies and how are they determined?
Apparently the Blood Alcohol Concentration (BAC) is measured differently in different parts of the world. Just for reference:
0.1 g alcohol in 100 mL blood equals:
0.1%(U.S., Canada, Australia)
1 ‰ = 1 permillegrams alcohol per 1 liter blood (EU)
22 mmol/L(in hospitals) millimols alcohol per liter blood.