A Stamford, Conn., man was arrested at the Westchester County Airport yesterday when he tried to board a plane with a piece of explosive detonating cord in his carry-on luggage, police said. Westchester County Public Safety Commissioner Thomas Belfiore said the man works for a company that sells explosive detection equipment and was on his way to St. Louis to demonstrate a piece of equipment. When a device used by baggage screeners indicated the presence of explosive material, they asked the man if he knew why. “He said, ‘Oh, it’s probably the explosive material in my bag,’ ” Belfiore said. “This prompted an interesting response on the part of the screeners and the police officers involved, to put it mildly.” Full Story