MAGNETIC COMPASS Russian patent published in 2003 - IPC

FIELD: navigational instrumentation engineering. SUBSTANCE: magnetic compass has case 1 with base 2 and transparent cover 3, illumination unit 4, magnetosensitive element 8 with supports 11, 12 and valve 10 for building-up excessive pressure. Interior of case 1 consists of two chambers 5 and 6 which are filled respectively with compressed gas and buoyant fluid. Flexible member 7 is placed at interface of two media. This member may be used as seal over upper and lower butts of case. Valve is made in form of flat spring provided with sealing ring. Base 2 of case is made from titanium. EFFECT: improved operating characteristics. 4 cl, 2 dwg