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Steel Making

The Forging Of Steel
So much depends upon the forging of steel that this operation...

Heat Treatment Of Steel
Heat treatment consists in heating and cooling metal at defin...

Bessemer Process
The bessemer process consists of charging molten pig iron int...

Heat-treating Department
The heat-treating department occupies an L-shaped building. ...

Connecting Rods
The material used for all connecting rods on the Liberty engi...

The Penetration Of Carbon
Carburized mild steel is used to a great extent in the manufa...

Temperature For Annealing
Theoretically, annealing should be accomplished at a tempera...

Chromium when alloyed with steel, has the characteristic func...

Testing And Inspection Of Heat Treatment
The hard parts of the gear must be so hard that a new mill f...

SULPHUR is another element (symbol S) which is always found i...

The Electric Process
The fourth method of manufacturing steel is by the electric f...

Temperatures To Use
As soon as the temperature of the steel reaches 100 deg.C. (...

Carbon-steel Forgings
Low-stressed, carbon-steel forgings include such parts as car...

Complete Calibration Of Pyrometers
For the complete calibration of a thermo-couple of unknown e...

Mushet And Bessemer
That Mushet was "used" by Ebbw Vale against Bessemer is, perh...

Silicon prevents, to a large extent, defects such as gas bubb...

Detrimental Elements
Sulphur and phosphorus are two elements known to be detrimen...

Rate Of Absorption
According to Guillet, the absorption of carbon is favored by ...

Properties Of Alloy Steels
The following table shows the percentages of carbon, manganes...

MANGANESE is a metal much like iron. Its chemical symbol is M...

Compensating Leads


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.

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Previous: Correction By Zero Adjustment

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