All objects emit measurable infrared energy.
The FT-50 uses special optics to gather infrared energy from a target surface and focuses this energy onto a custom detector. At that point, the detector will convert the infrared energy into an electrical signal proportionate to the temperature of the target surface. The final outcome is a digital temperature measurement in degrees Fahrenheit or Centigrade. It's easy to operate the FT-50. Simply point at the desired target, press and hold the on button for the temperature to display no contact is ever needed.