While working on a sermon the pastor heard a knock at his office door. "Come in," he invited. A sad-looking man in threadbare clothes came in, pulling a large pig on a rope. "Can I talk to you for a minute?" asked the ma... Read more of Jesus Is Watching at Free Jokes.caInformational Site Network Informational
   Home - Steel Making - Categories - Manufacturing and the Economy of Machinery

Steel Making

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

Introduction Of Carbon
The matter to which these notes are primarily directed is the...

Annealing Method
Forgings which are too hard to machine are put in pots with ...

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

A combination of the characteristics of nickel and the charac...

Annealing Work
With the exception of several of the higher types of alloy s...

Hardening High-speed Steels
We will now take up the matter of hardening high-speed steels...

Heating Of Manganese Steel
Another form of heat-treating furnace is that which is used ...

The Care Of Carburizing Compounds
Of all the opportunities for practicing economy in the heat-t...

Properties Of Steel
Steels are known by certain tests. Early tests were more or l...

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

Calibration Of Pyrometer With Common Salt
An easy and convenient method for standardization and one whi...

Carbon Steels For Different Tools
All users of tool steels should carefully study the different...

Heat Treatment Of Lathe Planer And Similar Tools
FIRE.--For these tools a good fire is one made of hard foundr...

Steel is hardened by quenching from above the upper critical....

High-chromium Or Rust-proof Steel
High-chromium, or what is called stainless steel containing f...

Shrinking And Enlarging Work
Steel can be shrunk or enlarged by proper heating and cooling...

The material used for all gears on the Liberty engine was sel...

Open Hearth Process
The open hearth furnace consists of a big brick room with a l...

Placing Of Pyrometers
When installing a pyrometer, care should be taken that it re...

Optical System And Electrical Circuit Of The Leeds & Northrup Optical Pyrometer


For extremely high temperature, the optical pyrometer is
largely used. This is a comparative method. By means of the rheostat
the current through the lamp is adjusted until the brightness of
the filament is just equal to the brightness of the image produced
by the lens L, Fig. 123, whereupon the filament blends with or
becomes indistinguishable in the background formed by the image
of the hot object. This adjustment can be made with great accuracy
and certainty, as the effect of radiation upon the eye varies some
twenty times faster than does the temperature at 1,600 deg.F., and some
fourteen times faster at 3,400 deg.F. When a balance has been obtained,
the observer notes the reading of the milliammeter. The temperature
corresponding to the current is then read from a calibration curve
supplied with the instrument.

As the intensity of the light emitted at the higher temperatures
becomes dazzling, it is found desirable to introduce a piece of red
glass in the eye piece at R. This also eliminates any question
of matching colors, or of the observer's ability to distinguish
colors. It is further of value in dealing with bodies which do
not radiate light of the same composition as that emitted by a
black body, since nevertheless the intensity of radiation of any
one color from such bodies increases progressively in a definite
manner as the temperature rises. The intensity of this one color
can therefore be used as a measure of temperature for the body
in question. Figures 124 to 126 show the way it is read.

Next: Correction For Cold-junction Errors

Previous: Leeds And Northrup Optical Pyrometer

Add to del.icio.us Add to Reddit Add to Digg Add to Del.icio.us Add to Google Add to Twitter Add to Stumble Upon
Add to Informational Site Network

Viewed 3642