How do those walk-through scanners in libraries know if you’re taking a book without borrowing it, especially if those books don’t have metal inserts or anything like that?

Question

How does the library borrowing system work? and how come even if there is no obvious metal insert in the book those gates still know when and when not to beep if the book has or hasn’t been borrowed?

In: Technology

Answer 1

Answer: They actually have the metal inserts you think aren’t there. They are usually concealed as a small stick w the magnetic strip on it in the spine of the dust jacket, or under an extra adhered sheet in the front or back of the book.