GB1361257A - Radiation pyrometer - Google Patents

Abstract

1361257 Thermoelectric devices INSTITUT NATIONAL DE LA RECHERCHE AGRONOMIQUE 27 Aug 1971 [27 Aug 1970] 40319/71 Heading H1K A pyrometer comprises a transparent housing containing a plurality of thermocouples constituted by a constantan strip plated on to an insulating substrate and engraved to form a castellated or saw-tooth shaped circuit, one half of each saw-tooth or crenel bearing an electrolytic copper deposit, the ends of the saw teeth or crenels being directly coated with layers of radiation absorbing and reflective materials as appropriate. As shown, Fig. 2, a thin insulating support, e.g. of epoxy resin is plated with a constantan sheet which is chemically engraved to form a castellated strip which is selectively electroplated with copper to form a plurality of thermocouples comprising the exposed constantan strips 8 and the copper-plated strips 9, the ends of the copper-plated sections defining the positions of the junctions. Alternate junctions are coated with radiation absorbing and reflective materials by applying layers 11 and 12 of black and white paint respectively over the junctions. The resulting device is mounted in a transparent glass tube under tension, the tube containing silica gel and carrying a spirit level aligned with the plane of the thermocouple strip. The lower face of the tube is masked by an aluminium sheet. The white and black paint may be replaced by a vacuum deposited layer of metal and a coating of a material having 'black-body' characteristics, respectively.