Neutrally buoyant magnetic sensor for borehole magnetometer

A magnetic sensor for borehole magnetometer, the magnetic sensor for borehole magnetometer comprising:

• an upper/bottom-opened pipe-shaped housing;
• a frame installed at an inside of said upper/bottom-opened pipe-shaped housing;
• an upper-opened magnetic sensor part installed at a bottom side of said frame;
• a lid covering an opened upper side of said upper-opened magnetic sensor part;
• a magnetic sensor disposed at an inside of the said upper-opened magnetic sensor part to measure a magnetic force;
• an upper spring coupled to an upper side of said magnetic sensor;
• a bottom spring coupled to a bottom side of said magnetic sensor;
• a first fixing groove is formed on a bottom surface of said lid, said first fixing groove being coupled to an upper end of said upper spring;
• a second fixing groove is formed at a lower portion of said upper-opened magnetic sensor part, said second fixing groove being coupled to a lower end of said bottom spring;
• and
• said magnetic sensor part being filled therein with a liquid to damp a vibration when the vibration is generated during vertical movement of said magnetic sensor;
• a spring stopper, attached at both lateral sides of said magnetic sensor, to prevent said upper spring and said bottom spring from rotating;
• and
• said upper spring and said bottom spring being fitted into upper and bottom sides of said magnetic sensor up to both distal ends of said spring stopper;
• and
• said spring stopper including a groove to fix said upper spring and said bottom spring;
• said lid including, at a center thereof, a through hole to pass a magnetic sensor cable therethrough;
• said liquid filling said magnetic sensor part having a same specific gravity as said magnetic sensor to enable said magnetic sensor to neutralize buoyance inside said liquid;
• said lid being screw-connected with said magnetic sensor part;
• said magnetic sensor including an upper lid and a bottom lid, said upper lid covering an opened upper side of said upper/bottom-opened pipe-shaped housing, said bottom lid covering an opened side of said upper/bottom-opened pipe-shaped housing.