Table Of ContentPeter E. Glaser
Editors
Raymond F. Walker
Thermal Imaging
Techniques
Proceedings of a Conference Held
October 4–5, 1962, at Arthur D. Little,
inc., Cambridge, Massachusetts
THERMAL
IMAGING
TECHNIQUES
THERMAL
IMAGING
TECHNIQUES
Proceedings of a Conference
Held October 4-5, 1962
at Arthur D. Little, Inc.,
Cambridge, Massachusetts
Edited by
Peter E. Glaser
Arthur D. Little, Inc.
and
Raymond F. Walker
National Bureau of Standards
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Springer Science+Business Media, LLC
1964
Library of Congress Catalog Card Number 64-19979
ISBN 978-1-4899-5647-7 ISBN 978-1-4899-5645-3 (eBook)
DOI 10.1007/978-1-4899-5645-3
© 1964 Springer Science+Business Media New York
Originally published by Plenum Press in 1964.
Softcover reprint ofthe hardcover 1st edition 1964
INTRODUCTION
The principle of focusing the image of the sun or an incandescent source
onto the surface of a body in order to heat it to a high temperature has been
known since ancient times. However, it is only in recent years that serious
consideration has been given to the utilization of this heating technique in
industrial and domestic applications, and in research in high-temperature
chemistry and physics. Early investigators used the sun as the source of
energy almost exclusively, and several conferences to discuss the progress
made with the solar heating devices have been held in various parts of the
world. For research purposes, however, solar furnaces have certain
disadvantages-e. g., they are "outdoor" devices, much dependent on the
weather and climate. In research increasing attention has therefore been
paid to possible alternative sources that would make operation under more
conventional laboratory conditions possible.
The carbon arc is one such source which evolved from this activity, and
is in fact now most commonly used for research purposes. The introduction
of the arc has led to the study of a wide range of physical and chemical
properties of substances using imaging techniques, and a conference was
therefore organized to assess both the progress which has been made and
the problems which remain. The proceedings of the conference form the
substance of this book.
The conference is believed to have been the first to be devoted primarily
to the application of imaging techniques to research, and also the first in
which the use of electrical sources was of more dominant interest than that
of solar furnaces. In many instances, however, the experimental techniques
described in this volume would be equally applicable with either type of
source.
Thermal imaging techniques have in principle a number of advantages
for research purposes. One advantage is that they permit experiments to
be carried out in the 1000-3500°C temperature range under extremely pure
conditions or in strongly oxidizing or reducing atmospheres-chemical
conditions which are not easy to reproduce using more conventional electrical
or chemical heating techniques. This particular advantage arises because
the sample can be completely isolated from the heat source, and except for
the radiation falli.ng on it, disturbing electric fields or reactive furnace
gases and components can be excluded. At the same time any desired
atmosphere can be chosen to surround the sample, or it can be exposed to a
high vacuum.
While arc imaging techniques are attractive in principle, early research
ers found that difficult problems arise when one wishes to maintain a sample
under a constant heat flux or a steady temperature for long periods of time.
Here the problem of temperature measurement also introduced several diffi
culties and uncertainties. Attempts have been made, therefore, to find new
sources which would not suffer from the shortcomings of the arc, and several
v
vi INTRODUCTION
of the papers presented at the conference are concerned with this problem.
Many ingenious devices have been constructed to measure the heat flux inci
dent upon a sample, and several of these are described in the following
papers. However, the difficulty of measuring temperatures accurately is
still not completely solved. It seem probable from the evidence presented
here that instrumentation is no longer the major problem in accurate tem
perature measurement. It is a better understanding of the temperature
gradients and thermal conditions prevailing at the heated sample surface
which is now required.
One of the striking results of the conference was the evidence produced
on the range of usefulness of imaging techniques. The sparsity of data on
the physics and chemistry under the conditions which are the particular
forte of image furnaces makes it profitable to obtain even qualitative infor
mation only roughly related to the International Practical Temperature Scale.
For this reason more extensive use has been found for thermal imaging
techniques than might be indicated by a consideration of the practical
problems involved in applying the techniques. Examination of the following
papers will show that not only have attempts been made to study a wide range
of physical and chemical properties of substances, but imaging techniques
have also been applied to such difficult-to-control processes as crystal
growth and zone refining.
These applications demonstrate that imaging techniques have graduated
from the stage of being laboratory curiosities and can take their place with
such competing high-temperature techniques as electron beams and lasers.
The aim of publishing the proceedings of the conference is to make both the
progress and the outstanding problems in the field more widely known, with
the hope that still more fruitful application of the techniques will result and
that study of associated problems will be stimulated.
ACKNOWLEDGMENTS
On behalf of all participants at the Conference it remains to express our
appreciation of the efforts ofmanypeoplewhomade the Conference possible.
Particular acknowledgment is due to the following, who not only presided over
individual sessions of the Conference, but added their comments and criti
cisms of the papers as part of the editorial review: Professor J. Drowart,
Universite Libre de Bruxelles, Belgium; Dr. A. J. Drummond, The Eppley
Laboratory Inc., Newport, Rhode Island; Dr. Nevin K. Hiester, Stanford Re
search Institute, Menlo Park, California; and Dr. W. W. Lozier, National
Carbon Co., Parma, Ohio. Thanks are also due to the authors of the papers
who reduced to minimum proportions the task of editing their manuscripts.
Finally a special word of appreciation is due John Criden whose efforts
were invaluable at every stage in the organization of the conference.
Peter E. Glaser
Arthur D. Little, Inc.
Raymond F. Walker
National Bureau of Standards
CONTENTS
Imaging Furnace and Radiation Source Development
An Arc Imaging Furnace for Solid Propellant Ignition Studies
by G. E. Dolan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
An Arc Imaging Furnace System for Studying the Ignition of Solid
Propellants
by A. L. Camus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
A Thermal Radiation Heat Source and Imaging System for Biomedical
Research
by D. L. Richardson . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Investigation of Thermal Imaging Techniques
by T. S. Laszlo and P. J. Sheehan. . . . . . . . . . . . . . . . . . . . . . 33
The Carbon Vapor Lamp
by G. P. Ploetz. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
A Four-Hundred Kilowatt Pressurized Arc Imaging Furnace
by J.C. Cook.............................. 55
The Double Parabolic Arc Image Furnace
by P. E. Evans. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
High-Wattage Xenon and Mercury Vapor Compact Arc Lamps as
Radiation Sources for Imaging Furnaces
by W. E. Thouret and H. S. Strauss. . . . . . . . . . . . . . . . . . . . . 91
Instrumentation and Measurement Techniques
Spectroradiometric Instruments and Techniques for Use in Imaging
Furnaces
by L. Eisner, D. W. Fisher, and R. F. Leftwich . . . . . . . . . . . . 113
Measurement of Spectral Reflectance and Emissivity of Specular and
Diffuse Surfaces in the Carbon Arc Image Furnace
by M. R. Null and W. W. Lozier. . . . . . . . . . . . . . . . . . . . . . . 131
Concerning Several Devices for the Utilization of Imaging Furnaces
by M. Foex . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
Thermal Image Description and Measurement
by E. S. Cotton .................. . 163
Calibration of Sources for Imaging Furnaces
by C. P. Butler. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
vii
viii CONTENTS
Crystal Growth
Crystal Growth in the System Fe0-Mg0-Fe203
by F. A. Halden .................... . 193
Carbon Arc Imaging Furnace and Its Application to Single-Crystal
Growth
by M. Kestigian, G. j. Goldsmith, and M. Hopkins. . . . . . . . . . . 201
Arc Imaging Furnace Crystal Growth
by R. P. Poplawsky . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209
Experimental Procedures
The Solubility of Water Vapor in Molten Alumina
by J. J. Diamond and A. L. Dragoo . . . . . . . . . . . . . . . . . . . . . 225
The Effect of Thermal Radiation on Textile Materials: Part I
by A. j. McQuade and E. T. Waldron . . . . . • . . . . • . . . . . 229
The Effect of Thermal Radiation on Textile Materials: Part II
by J. B. Berkowitz-Mattuck . . . . . . . . . . . . . . . . . . . . . . . . . 243
Ablation and Analytical Measurements Using an Arc Image Furnace
by j. E. Brownsword, j. K. Phillips, and M. T. Conger. . . . . . . . 247
Heat Capacities of Boron Nitride and Aluminum Oxide Using an Arc
Imaging Furnace
by H. Prophet and D. R. Stull . . . . . . . . . . . . . . . . . . . . . . . . 261
A Radiation Technique for Measuring the Freezing Points of
Refractory Oxides
by D. F. Comstock and A. L. Camus . . . . . . . . . . . . . . . . . . . 271
Index. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279
Imaging Furnace
and Radiation Source Development
Chapter 1
An Arc Imaging Furnace for Solid Propellant
Ignition Studies
Gerald E. Dolan*
Thiokol Chemical Corporation
Elkton Division
Elkton, Maryland
A. INTRODUCTION
The arc imaging furnace has proven to be a versatile instrument for
studying solid propellant ignition. The features which make this instrument
attractive are: (1) reproducible flux levels, (2) clean source of heat, and
(3) what may be termed 'instant' heat, i.e., the high blackbody temperatures
may be turned on and off instantly without any appreciable heat losses,
which for other high-temperature devices constitute a significant source
of error.
B. BACKGROUND
From an historical aspect, the ignition of solid propellant has been a
hit or miss proposition-an art instead of a science. In the early days if
reliable ignition was not achieved, more igniter material was added. Al
though pyrotechnic devices are still quite widespread, improved reliability
has resulted with the use of PYROGEN® igniters (a registered trademark
of Thiokol Chemical Corporation for a small rocket motor which exhausts
into and ignites a larger unit). Hypergolic ignition, which has received
considerable attention recently, utilizes an easily oxidized (fuel-rich)
surface which is sprayed with a strong oxidizing agent. Although reliability
makes hypergolic ignition desirable, this method suffers from excessive
ignition delays and the need for additional hardware to assure contact be
tween the two materials.
Experience has shown that ignition is achieved principally by conduction
and radiation. For instance, a small strand of composite solid propellant
may be ignited in about 2 to 5 sec by placing it in contact with a lighted
cigarette. The heat is transferred to the surface of the propellant by the
impingement of hot gases and/or hot particles. Hot-gas ignition is nor
mally achieved by squib ignition of nitrate esters (nitroglycerine-nitro
cellulose compositions) or other pyrophoric materials which in turn im
part sufficient energy to bring about steady-state ignition of the propellant.
In hot particle ignition, incandescent particles come in contact with the
propellant surface, and a steady-state burning is achieved from the many
"starts" induced by the particles.
*Development Chemist.
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