| There was once a little girl who was very, very poor. Her father and mother had died, and at last she had no little room to stay in, and no little bed to sleep in, and nothing more to eat except one piece of bread. So she said a prayer, put on ... Read more of THE STAR DOLLARS at Children Stories.ca |  Informational.caPrivacy |
Steel MakingForging High-speed SteelHeat very slowly and carefully to from 1,800 to 2,000 deg.F.... Plant For Forging Rifle Barrels The forging of rifle barrels in large quantities and heat-tre... Heat Treatment Of Steel Heat treatment consists in heating and cooling metal at defin... The Penetration Of Carbon Carburized mild steel is used to a great extent in the manufa... Carburizing Material The simplest carburizing substance is charcoal. It is also th... Molybdenum Molybdenum steels have been made commercially for twenty-five... Leeds And Northrup Optical Pyrometer The principles of this very popular method of measuring tempe... Detrimental Elements Sulphur and phosphorus are two elements known to be detrimen... Hints For Tool Steel Users Do not hesitate to ask for information from the maker as to t... Separating The Work From The Compound During the pulling of the heat, the pots are dumped upon a ca... Refining The Grain This is remedied by reheating the piece to a temperature slig... Pyrometers Armor plate makers sometimes use the copper ball or Siemens' ... Temperature Recording And Regulation Each furnace is equipped with pyrometers, but the reading an... Affinity Of Nickel Steel For Carbon The carbon- and nickel-steel gears are carburized separately... Gears The material used for all gears on the Liberty engine was sel... Manganese MANGANESE is a metal much like iron. Its chemical symbol is M... Alloying Elements Commercial steels of even the simplest types are therefore p... Carbon In Tool Steel Carbon tool steel, or tool steel as it is commonly called, us... Cutting-off Steel From Bar To cut a piece from an annealed bar, cut off with a hack saw,... Standard Analysis The selection of a standard analysis by the manufacturer is t... |
Compensating LeadsCategory: PYROMETRY AND PYROMETERS By the use of compensating leads, formed of the same material as the thermo-couple, the cold junction can be removed from the head of the thermo-couple to a point 10, 20 or 50 ft. distant from the furnace, where the temperature is reasonably constant. Where greater accuracy is desired, a common method is to drive a 2-in. pipe, with a pointed closed end, some 10 to 20 ft. into the ground, as shown in Fig. 128. The compensating leads are joined to the copper leads, and the junction forced down to the bottom of the pipe. The cold junction is now in the ground, beneath the building, at a depth at which the temperature is very constant, about 70 deg.F., throughout the year. This method will usually control the cold-junction temperature within 5 deg.F. Where the greatest accuracy is desired a compensating box will overcome cold-junction errors entirely. It consists of a case enclosing a lamp and thermostat, which can be adjusted to maintain any desired temperature, from 50 to 150 deg.F. The compensating leads enter the box and copper leads run from the compensating box to the instrument, so that the cold junction is within the box. Figure 129 shows a Brown compensating box. If it is desired to maintain the cold junction at 100 deg.: the thermostat is set at this point, and the lamp, being wired to the 110- or 220-volt lighting circuit, will light and heat the box until 100 deg. is reached, when the thermostat will open the circuit and the light is extinguished. The box will now cool down to 98 deg., when the circuit is again closed, the lamp lights, the box heats up, and the operation is repeated. Next: Brown Automatic Signaling Pyrometer Previous: Correction By Zero Adjustment
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