The direct application of interferometric techniques to the master metering
system for the AHAC is the only known method available and in existence
which can automatically provide the total accumulative accuracy and resolu-
tion as is called for in the AHACME specification requirements. This
interferometric metering system does not rely upon man-made scales
and is thus, as previously explained, a primary or absolute measurement
system. The proposed interferometers will not require continual com-
pensation for ambient atmospheric variations, as is presently necessary
with most absolute interferometers. This freedom from compensation
represents a significant improvement,
A substantial amount of development work will be required to ensure nec-
essary interferometer performance. Such work is greatly facilitated by
recent breakthroughs in the art of long-path-length interferometery, in
addition to both new and continued development work that Link has been
undertaking independently. This background provides Link with the addi-
tional confidence that it will be able to provide a usable and trouble-free
system for the AHAC specification requirements.
BACKGROUND
Link is the only commercial manufacturer of automatic reading interfero-
meters in the world. The experience and techniques gained during the re-
search and development and production of this device, the Link Fringe-
count Micrometer Interferometer, during the past six years, places this
organization in a unique position. Link has produced a substantial quantity |
of the Fringecount Interferometers. These units are installed in a wide
variety of industrial and government laboratories and are principally used
for the absolute calibration of master gage blocks and the measurement of
balls and cylinders. In addition, the Fringecounts are used for a wide
variety of special purposes, such as measurement of thermal coefficients
of expansion, thin sheet stock material, sonar wavelengths, and others.
The Fringecount Micrometer Interferometer has, and is, establishing an
eminently successful position in the field of ultra-high precision measure-
ments,
