OVI Science: A Quick Explanation of Henry’s Law
OVI science is a term used to describe the myriad disciplines of science involved in the defense of OVI (drunk driving cases). Here is a quick explanation of Henry’s Law.
If you have ever opened a cold beer you are familiar with Henry’s Law. As the drink is poured small gas bubbles escape into the atmosphere. Why? It is due to the decrease in pressure caused by opening the bottle and the increased if you pour the liquid into a glass which is hotter than the refrigerated beer bottle.
We can use OVI science to attack the operation of Henry’s Law in the accusation of drunk driving when a person is over-heated due to an illness or physical exertion like dancing. The higher the temperature, the higher a breath test will be according to science. Breathing patterns can also affect the concentration of alcohol in a breath sample. This variation is primarily caused by the difference between the ambient air temperature and that of the human body. Since it is impossible for any breath testing device to sample the air exchange at the alveolar level, it has to assume that the air coming out is of an equivalent alcohol concentration based on Henry’s Law. It cannot and does not take into account any differences in the individual, the individual’s lungs or the differences in temperature between the ambient air and the sample.