| 摘要 |
721,148. Automatic temperature control systems. LEEDS & NORTHRUP CO. Feb. 6, 1951 [Feb. 7, 1950], No. 2925/51. Class 38 (4). [Also in Group XL (b)] In a system for measuring or measuring and controlling the temperature of a surface 10, Fig. 1, of heated material 11 an illuminator surface 16 is placed adjacent surface 10 to define a measuring zone therebetween, the illuminator being provided with heaters and having a peripheral area 40a for inwardly directing energy received by the peripheral area, and a pyrometer 25 is positioned to receive energy from the zone. Black body conditions are simulated in the measuring zone by the addition to the radiant energy emitted directly from the restricted portion of surface 10 so as to enter pyrometer 25, of reflected energy emitted from other parts of surface 10 opposite the illuminator, and from the illuminator surface 16. To prevent radiant energy within the zone from escaping and external energy from entering, the peripheral portion 40a of the illuminator is formed with saw-tooth cuts whose surfaces lie at angles of 60 and 30 degrees respectively to the flat central portion of the illuminator and skirts 45 are provided. A heater-controller 18 receiving the output of a thermometer such as a resistance thermometer or thermocouple 20 in contact with illuminator 16, maintains the latter at the desired temperature of surface 10 by means of electrical heater 17. Any temperature variation of surface 10 changes the radiation received by the sensitive element 24 of the total radiation pyrometer 25 and the resultant rotation of the slidewire 26 by means of the mechanical relay MR, controlled by galvanometer G, in order to rebalance the potentiometer measuring circuit which includes battery B, and resistor 33, causes both a pen and indicator 29 to move relatively to a record chart 30 and scale 31 and also to make the temperature controller 32 change the setting of the valve 15 or the like to increase or decrease the heat applied by chamber 14 to the moving material 11. The valve 15 may be cyclically operated between " on " and " off " positions or may be adjusted to an intermediate position. The illuminator 16 which may be of polished chromium plated iron or copper, polished stainless steel or aluminium, is heated by the strip heaters such as 46, 48, 49, Fig. 8, which are clamped thereto, and covered by glass wool 60, held in place by cap 63. The pyrometer 25 is secured to illuminator 16 at an angle of 60 degrees thereto and may have its lower end cooled by a water jacket. The skirts 45 of Fig. 1, may be formed of blocks 64, surrounding the edges of the illuminator so as to serve also as bumpers, the assembly being mounted by brackets 58. In a modification the peripheral area 40a is roughened or sand-blasted or may comprise oxidized copper, platinum black or shellac. Specification 721,147, [Group XL (b)], is referred to. |
