Comment No it does not see the difference (Score 5, Informative) 647
There has been some news here in the Netherlands about it and no it can't see whether you are under the influence or have used it in the last 24 hours or even days before depending on the drug. Most drug effect wear off after sleep and this machine won't know the difference. In the Netherlands this is such a big problem that drug prevention units like Trimbos are advising against its use as it will create more problems than solve. But maybe it works better in countries that prosecute users anyway.