Head assembly for multiposition borehole extensometer

Patent · Sat Jan 01 00:00:00 EST 1983

OSTI ID:864546

Frank, Donald N ^[1]

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1. Livermore, CA

A head assembly for a borehole extensometer and an improved extensometer for measuring subsurface subsidence. A plurality of inflatable anchors provide discrete measurement points. A metering rod is fixed to each of the anchors which are displaced when subsidence occurs, thereby translating the attached rod. The head assembly includes a sprocket wheel rotatably mounted on a standpipe and engaged by a chain which is connected at one end to the metering rod and at the other end to a counterweight. A second sprocket wheel connected to the standpipe also engages the chain and drives a connected potentiometer. The head assembly converts the linear displacement of the metering rod to the rotary motion of the second sprocket wheel, which is measured by the potentiometer, producing a continuous electrical output.

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
• DOE Contract Number: W-7405-ENG-48
• Assignee: United States of America as represented by United States (Washington, DC)
• Patent Number(s): US 4382335
• OSTI ID: 864546
• Country of Publication: United States
• Language: English

Related Subjects

head
assembly
multiposition
borehole
extensometer
improved
measuring
subsurface
subsidence
plurality
inflatable
anchors
provide
discrete
measurement
metering
rod
fixed
displaced
occurs
translating
attached
sprocket
wheel
rotatably
mounted
standpipe
engaged
chain
connected
counterweight
engages
drives
potentiometer
converts
linear
displacement
rotary
motion
measured
producing
continuous
electrical
output
linear displacement
head assembly
rotatably mounted
rotary motion
electrical output
provide discrete
measuring subsurface
continuous electrical
surface subsidence
borehole extensometer
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