Pop-Up Thermometer
Turkey Pop-Up Thermometer was patented by George Kliewer in 1966. He received Patent Number 3,280,629. Originally called the Thermally Responsive Signaling Device, the invention was modeled somewhat on indoor sprinkler systems. An outer housing is inserted into the meatiest part of the bird. An inner rod is propped up by a spring, and a pin keeps the spring from popping up. The pin, made of either metal or wax, melts at a predetermined temperature and releases the spring. The spring pushes up the inner rod, signaling that the meat has reached the desired temperature. About 30 million pop-up thermometers are sold every year. Children can learn more at: Pop-Up.