FIELD: mining industry instrumentation. SUBSTANCE: improved reliability in operation of bottom-hole geophysical instrument is achieved by elimination of spontaneous unscrewing of threaded plug in protective housing. Body of bottom-hole geophysical instrument has protective housing, threaded plugs with radial protrusions, and made in them are two rows of turbine blades. Incline of upper row of blades relative to axis of instrument coincides with direction of thread incline, and incline of lower row of blades is opposite to aforesaid direction. EFFECT: higher efficiency. 3 dwg
