| O God that created me so helpless, Strengthen my belief and make it firm. Command an angel to come from Paradise, And take up his abode in my dwelling, To protect me from every trouble That wicked folks are putting in my way; Jesus, that did... Read more of The Hymn Of Donald Ban at Scary Stories.ca |  Informational.caPrivacy |
Steel MakingStandard AnalysisThe selection of a standard analysis by the manufacturer is t... Steel Before The 1850's In spite of a rapid increase in the use of machines and the ... Separating The Work From The Compound During the pulling of the heat, the pots are dumped upon a ca... The Electric Process The fourth method of manufacturing steel is by the electric f... William Kelly's Air-boiling Process An account of Bessemer's address to the British Association w... Temperature Recording And Regulation Each furnace is equipped with pyrometers, but the reading an... A Chromium-cobalt Steel The Latrobe Steel Company make a high-speed steel without tun... Rate Of Cooling At the option of the manufacturer, the above treatment of gea... Making Steel Balls Steel balls are made from rods or coils according to size, st... Ebbw Vale And The Bessemer Process After his British Association address in August 1856, Besseme... Optical System And Electrical Circuit Of The Leeds & Northrup Optical Pyrometer For extremely high temperature, the optical pyrometer is lar... Crucible Steel Crucible steel is still made by melting material in a clay or... Restoring Overheated Steel The effect of heat treatment on overheated steel is shown gra... High Speed Steel For centuries the secret art of making tool steel was handed ... Annealing In Bone Steel and cast iron may both be annealed in granulated bone. ... Open Hearth Process The open hearth furnace consists of a big brick room with a l... Hardness Testing The word hardness is used to express various properties of me... Heating Although it is possible to work steels cold, to an extent de... Manganese MANGANESE is a metal much like iron. Its chemical symbol is M... Calibration Of Pyrometer With Common Salt An easy and convenient method for standardization and one whi... |
Pyrometry And PyrometersCategory: PYROMETRY AND PYROMETERS A knowledge of the fundamental principles of pyrometry, or the measurement of temperatures, is quite necessary for one engaged in the heat treatment of steel. It is only by careful measurement and control of the heating of steel that the full benefit of a heat-treating operation is secured. Before the advent of the thermo-couple, methods of temperature measurement were very crude. The blacksmith depended on his eyes to tell him when the proper temperature was reached, and of course the color appeared different on light or dark days. Cherry to one man was orange to another, and it was therefore almost impossible to formulate any treatment which could be applied by several men to secure the same results. One of the early methods of measuring temperatures was the iron ball method. In this method, an iron ball, to which a wire was attached, was placed in the furnace and when it had reached the temperature of the furnace, it was quickly removed by means of the wire, and suspended in a can containing a known quantity of water; the volume of water being such that the heat would not cause it to boil. The rise in temperature of the water was measured by a thermometer, and, knowing the heat capacity of the iron ball and that of the water, the temperature of the ball, and therefore the furnace, could be calculated. Usually a set of tables was prepared to simplify the calculations. The iron ball, however, scaled, and changed in weight with repeated use, making the determinations less and less accurate. A copper ball was often used to decrease this change, but even that was subject to error. This method is still sometimes used, but for uniform results, a platinum ball, which will not scale or change in weight, is necessary, and the cost of this ball, together with the slowness of the method, have rendered the practice obsolete, especially in view of modern developments in accurate pyrometry. Next: Pyrometers Previous: Furnace Data
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