Head assembly for multiposition borehole extensometer
Description:
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…
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Date:
June 9, 1981
Creator:
Frank, D.N.
Partner:
UNT Libraries Government Documents Department