This breathalyser cost me 15£ and as you can see definitely registers acetone as isopropanol. Consider I don’t drink, so that is literally just ketones. To put it to a test both my husband (carbophagus) and I (ketoer) breathed in. While he was a pure zero, you can see I am basically over the legal limit for “drunk driving”, all due to being in a state of ketosis, burning dietary and body fat for energy (lost another 2lbs this week!). Link to get it from Amazon http://geni.us/breathketone
Basically one of the pathways for acetone (a ketone) metabolism is the conversion to isopropanol. The ‘ol’ at the end of isopropanol identifies it as an alcohol. The isopropanol in the breath is what the breathalyzer picks up. At this stage of breathalyzer development, the machines can’t differentiate between various alcohols and so registers them all as ethanol, the alcohol in booze.