| I love dreams where one doesn't have sex, but there's a knowing checmistry and you feel, when you wake up, that it's been better than sex alone. My dream last night was a good friend (colleague) and I taking photo's of a fantastic lightning storm... Read more of Taking 'Photos at My Dreams.ca |  InformationalPrivacy |
Steel MakingHigh Speed SteelFor centuries the secret art of making tool steel was handed ... Refining The Grain This is remedied by reheating the piece to a temperature slig... Silicon SILICON is a very widespread element (symbol Si), being an es... Piston Pin The piston pin on an aviation engine must possess maximum res... Take Time For Hardening Uneven heating and poor quenching has caused loss of many ve... Sulphur SULPHUR is another element (symbol S) which is always found i... Temperature Recording And Regulation Each furnace is equipped with pyrometers, but the reading an... Instructions For Working High-speed Steel Owing to the wide variations in the composition of high-speed... Annealing Method Forgings which are too hard to machine are put in pots with ... Cyanide Bath For Tool Steels All high-carbon tool steels are heated in a cyanide bath. Wi... Annealing Of High-speed Steel For annealing high-speed steel, some makers recommend using g... Phosphorus Phosphorus is one of the impurities in steel, and it has been... Classifications Of Steel Among makers and sellers, carbon tool-steels are classed by g... Alloying Elements Commercial steels of even the simplest types are therefore p... William Kelly's Air-boiling Process An account of Bessemer's address to the British Association w... Correction For Cold-junction Errors The voltage generated by a thermo-couple of an electric pyrom... A Chromium-cobalt Steel The Latrobe Steel Company make a high-speed steel without tun... Pickling The Forgings The forgings were then pickled in a hot solution of either ni... The Quenching Tank The quenching tank is an important feature of apparatus in c... Nickel-chromium A combination of the characteristics of nickel and the charac... |
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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