I'm in New Mexico. I visit my son in a facility three and a half hours away. Because I work all week, I can't get there very often, only on occasional weekends. This weekend, I was scanned by the ion scanner for the first time. I've never before seen one of these machines. I was horrified when I came back positive for heroin, and a very high count at that! I've never used an illegal drug of any kind. I do take a couple prescription medications. I need help. Do some of these cause the reading to be wrong? How long does the residue last? The staff admitted that they weren't accusing me of using drugs, just that I had come into contact with drugs. How can anyone prevent this contact if one doesn't know it's there? I'm very upset. I was not allowed to see my son and may not get up there for another month. Then if I test positive again, I'll be bared again. There has to be some recourse! [Editor's note: The "reading" was wrong because the gadgets simply don't work. All the prisons know that the gadgets don't work. Why are they still in use? Intimidation of visitors! It's time to sue the maker.]