Optical Mice Used To Detect Counterfeit Coins 123
JimXugle writes "El Mundo reports that Spanish researchers at The University of Lleida have used a modified optical mouse to detect counterfeit €2 coins (Original article, in Spanish) with a success rate comparable to that of an expert trained to do so. Details are to be published freely in the journal Sensors."
Re:How does it compare to a vending machine? (Score:3, Informative)
Vending machines rely on mechanical factors, mostly: Weight, size, metallic composition (measured by conductivity characteristics).
This one seems to focus on the graphics on the faces. It's complementary.
Fun fact #65 (Score:4, Informative)
Did you know that there are more than 260 different euro coins from 19 countries to present day!
Re:How does it compare to a vending machine? (Score:5, Informative)
Vending machine detectors are usually just magnets (at least in the US). Very few countries make their coins with enough iron, nickel, or cobalt to be magnetic, so a magnet can pick out most slugs (the usual form of counterfeiting used on vending machines). I know; I own vending machines.
Also, it's OT, but your sig annoys the crap out of me. I use whom correctly all the time, "intensive purposes" is retarded. Begging the question, though, seems to have actually changed meanings over the years, so, being a descriptivist, I'll give you that one.
Re:How does it compare to a vending machine? (Score:5, Informative)
My understanding was that the coin falls into a balanced cradle that measures the diameter and weight. If it's the wrong size it is rejected (and can fall through to another cradle that tests for a different value coin---and so on). If it is the right size but the wrong weight the cradle tips too far or not far enough and deposits it in the reject slot.
If it's the right size and weight then the coin drops between two magnets onto a little anvil. If the metallic composition is right the coin will slow just enough passing through the magnets to hit the anvil at the right place and speed to bounce into the accept slot. Anything else and it misses.
The end result is a very quick, accurate but cheap analysis of the coin's weight, size and metallic composition.
I know that's the way it used to work. Have they dumbed down the machines recently?
Re:Who counterfiets 2-Euro coins anyways? (Score:4, Informative)
I don't know about €2 coins, but loads of £1 coins are counterfeit -- perhaps 5% [greenend.org.uk]. The €2 (and 1) are bi-metallic though, so presumably harder to fake.
Under UK law (as that page explains), once you know a coin is counterfeit it's illegal to give it to anyone (except the police) or to keep it. Daft, but it means it's in my interest not to identify counterfeits. (Unless, possibly, I checked every time I was given change. But that's not realistic.)
Re:How does it compare to a vending machine? (Score:3, Informative)