ARRANGEMENT FOR CONTACTLESS DETERMINATION OF THERMAL RADIATION FROM AN INFRA-RED RADIATOR

摘要

Remote heat sensor has an IR photocell in a housing thermostatically kept at e.g. 70 degrees C, and may be mounted wherever convenient. The IR has a wavelength of approx. 8 mu and is focussed on the photoresistor by a lens doublet, one lens being made of CaFe and the other of indium antimonide, with an antireflective coating of silica. The photosensor is made of a semiconductor, pref. Indium antimonide, filled with inclusions of an eutectic material consisting of parallel needles spaced at intervals = the wavelength of the I.R. The crystalline needles have a higher electrical conductivity than the matrix. The inclusions may consist of nickel antimonide or FeSe, CoAs, CrSb, CrAs or MnSb.