Is there a seal that beeps on old USD bills?

There's a seal on every USD bill to the right on front side of every bill. When checked on the machine for checking money it beeps and that means the bill is real.


Now, my question is: do the old bills beep too? And I mean really old ones, like from the beginning of the 20th century.


Sources, please.|||http://en.wikipedia.org/wiki/Counterfeit鈥?/a>


should give a lot of information on this. As counterfeiters were getting smarter, governments were also keeping up with the technology. Very old ones? You may have to put one through a modern machine, which has magnetic, ultraviolet and other sensing mechanisms.