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UNITS AND CONVERSION FACTORS
E.J. ROSCHKE
PROPULSION DIVISION
JET PROPULSION LABORATORY

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NOTE:
Many years ago I was given a copy of this document, prepared in handwriting, some time in the early 1960’s. I did not know the author, E.J. Roschke. I have found it to be such a useful reference that I decided to have an electronic version prepared. Recently, I spoke with Dr.
Roschke, now retired from the Jet Propulsion Laboratory to learn of the document’s origin. In the early 1960’s a group of research engineers, largely having backgrounds in mechanical engineering, were engaged in the new field of electric propulsion. They experienced practical annoyances with the mingling of units from mechanical engineering, electrical engineering and physics. That situation motivated Dr. Roschke to assemble this material.
Although I have carefully checked the values given here, it is quite possible that some typographical errors remain. I will appreciate learning any corrections that should be made.
F.E.C. Culick
Mechanical Engineering
California Institute of Technology
October 2001

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UNITS AND CONVERSION FACTORS
Table of Contents
Section
I.
II.
III.
IV.
V.

VI.
VII.

Page

References
Decimal Multiples and Submultiples
Description of Units
Mechanical, Electric, Magnetic
Equivalent Units mksq System
Dimensions of esu and emu Electric and Magnetic Quantities
Dimensions and Units for Physical Quantities — mksq System
A. Mechanical
B. Thermal
C. Electric and Magnetic
Conversion of mksq Units to Gaussian Units
Conversion Factors
A. Plane Angle
B. Solid Angle
C. Length
D. Area
E. Volume
F. Mass
G. Density
H. Time
I. Speed
J. Force
K. Pressure
L. Energy, Work, Heat
M. Specific Energy
N. Specific Energy Per Unit Temp.
O. Power
P. Heat Flux
Q. Heat Transfer Coefficient
R. Thermal Conductivity
S. Absolute Viscosity
T. Kinematic Viscosity
AA. Electric Charge
BB. Electric Current
CC. Electric Potential
DD.

References: 1. Halliday, D. & Resnick, R., Physics – For Students of Science and Engineering, John Wiley, New York, 1960. 2. Forsythe, W.E., Smithsonian Physical Tables, 9th Revised Edition, Publ. 4169, Smithsonian Institution, Washington, D.C., 1954. 3. Scott, R.B., Cryogenic Engineering, D. Van Nostrand Inc., Princeton, New Jersey, 1959. 4. Hall, N.A., Thermodynamics of Fluid Flow, Second Printing with revisions, Prentice-Hall Inc., Englewood Cliffs, New Jersey, 1956. 5. Gray, D.E. (coordinating editor), American Institute of Physics Handbook, McGraw Hill Inc., New York, 1957.