A method and apparatus for determining the temperature of a hot body by a non-contact technique. It comprises a chopping disc 2 which may be disposed in the path of the radient heat energy from the object so providing a pulsed output of radient heat energy directed towards a pyroelectric element 7. Between...http://www.google.com.au/patents/US4693615?utm_source=gb-gplus-sharePatent US4693615 - Non-contact temperature measurement of a static or moving target
