THERMOMETRIC HOLE IN PERMAFROST GROUNDS Russian patent published in 1995 - IPC

FIELD: testing ground temperature. SUBSTANCE: thermometric hole in permafrost grounds has cased part with use of plastic pipe 4 with wood conical attachment 5 at its end and water-proof plug 8. Attachment 5 is located at least 1 m below the permafrost boundary, and casing-borehole annulus is filled with frozen filling material of local low-filtering ground. Filling material with water freezes up and expands to produce impermeable obstacle together with swelled attachment 5 for filtration of water layer of season thawing over walls. This prevents caving of hole walls. During measurement of temperature, thermometer is lowered into hole for time required for equalizing temperature of thermometer with that of hole, and lifted from hole to take readings. EFFECT: simplified process and cut down costs of hole construction and higher accuracy of measurement. 1 dwg