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Instruments \ Gravity \ Gravity Meters \
Name: |
Oertling Gravity Gradiometer |
Date: |
1931 |
Item Number: |
86.14.01 |
Donor: |
George A. McCalpin |
Type: |
N/A |
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Manufacturer:
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L. Oertling Ltd. |
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Description:
The following description was extracted from a short note in The
Leading Edge, Decemer 1988, on page 78.
The instrument pictured here is an Oertling gravity gradiometer
recently donated to the Museum of Exploration Geophysics by
George McCalpin. This instrument, which dates from the 1920s,
was the successor to the Eotvos beam torsion balance.
This system, which replaced the torsion balance beam with
masses of a circular nature rotating on a torsion wire, offered a
more portable method for making gravity measurements, and its
design minimized the gravitational effect of an approaching observer.
However, it was still a very time-consuming method. A single reading
was obtained every 25 minutes, and each station required five
different azimuth readings (so each station took more than two hours,
if everything went smoothly).
Shipping records indicate this particular instrument was the property
of Sun Oil Company in 1935, which was about the time the development
of the modern gravity meter caused this and other similar systems to
be phased out of routine operations.
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