VIEW THE MOBILE VERSION of Informational Site Network Informational
   Home - Steel Making - Categories - Manufacturing and the Economy of Machinery

Steel Making

Ebbw Vale And The Bessemer Process
After his British Association address in August 1856, Besseme...

Forging High-speed Steel
Heat very slowly and carefully to from 1,800 to 2,000 deg.F....

Correction For Cold-junction Errors
The voltage generated by a thermo-couple of an electric pyrom...

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

Phosphorus is one of the impurities in steel, and it has been...

Using Illuminating Gas
The choice of a carburizing furnace depends greatly on the fa...

Leeds And Northrup Optical Pyrometer
The principles of this very popular method of measuring tempe...

Heavy Forging Practice
In heavy forging practice where the metal is being worked at...

The Pyrometer And Its Use
In the heat treatment of steel, it has become absolutely nece...

Affinity Of Nickel Steel For Carbon
The carbon- and nickel-steel gears are carburized separately...

William Kelly's Air-boiling Process
An account of Bessemer's address to the British Association w...

Lathe And Planer Tools
TO FORGE.--Gently warm the steel to remove any chill is parti...

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

Separating The Work From The Compound
During the pulling of the heat, the pots are dumped upon a ca...

Chrome-nickel Steel
Forging heat of chrome-nickel steel depends very largely on ...

Hardening Carbon Steel For Tools
For years the toolmaker had full sway in regard to make of st...

Hardening Operation
Hardening a gear is accomplished as follows: The gear is tak...

Piston Pin
The piston pin on an aviation engine must possess maximum res...

Brown Automatic Signaling Pyrometer
In large heat-treating plants it has been customary to mainta...

Annealing Of Rifle Components At Springfield Armory
In general, all forgings of the components of the arms manufa...

Complete Calibration Of Pyrometers


For the complete calibration
of a thermo-couple of unknown electromotive force, the new couple
may be checked against a standard instrument, placing the two bare
couples side by side in a suitable tube and taking frequent readings
over the range of temperatures desired.

If only one instrument, such as a millivoltmeter, is available,
and there is no standard couple at hand, the new couple may be
calibrated over a wide range of temperatures by the use of the following

Water, boiling point 212 deg.F.
Tin, under charcoal, freezing point 450 deg.F.
Lead, under charcoal, freezing point 621 deg.F.
Zinc, under charcoal, freezing point 786 deg.F.
Sulphur, boiling point 832 deg.F.
Aluminum, under charcoal, freezing point 1,216 deg.F.
Sodium chloride (salt), freezing point 1,474 deg.F.
Potassium sulphate, freezing point 1,958 deg.F.

A good practice is to make one pyrometer a standard; calibrate it
frequently by the melting-point-of-salt method, and each morning
check up every pyrometer in the works with the standard, making the
necessary corrections to be used for the day's work. By pursuing
this course systematically, the improved quality of the product
will much more than compensate for the extra work.

The purity of the substance affects its freezing or melting point.
The melting point of common salt is given in one widely used handbook
at 1,421 deg.F., although chemically pure sodium chloride melts at
1,474 deg.F. as shown above. A sufficient quantity for an extended
period should be secured. Test the melting point with a pyrometer
of known accuracy. Knowing this temperature it will be easy to
calibrate other pyrometers.

Next: Placing Of Pyrometers

Previous: Calibration Of Pyrometer With Common Salt

Add to Add to Reddit Add to Digg Add to Add to Google Add to Twitter Add to Stumble Upon
Add to Informational Site Network

Viewed 3644