http://www.neptunusmedical.com..../diagnostic-instrume the measurement of the infrared energy radiated by the organism itself, its surface temperature can be accurately determined, which is the objective basis on which infrared radiation temperature measurement is based. An infrared thermometer consists of a lens to focus the infrared (IR) energy on to a detector, which converts the energy to an electrical signal that can be displayed in units of temperature after being compensated for ambient temperature variation.
This configuration facilitates temperature measurement from a distance without contact with the object to be measure