Methodology of Measuring Minite Remanence up to Submicron Tesla Level

The remanence remaining in a volcanic rock is one of important measurement data in geophysics field. The sample of a rock has the remnant magnetization up to 10-9 T. Generally the remote magnetic fields measured by SQUID gradiometer presume the remanence of a rock as a sample. We propose a new methodology by measuring a magnetic field inside a cylindrical hole in the rotating sample. We could develop the simple measurement without shield system and high sensitivity sensor. The paper described the measurement system and the measured results of the rock. We could measure the remanence of a volcanic stone quarried from the volcanic rocks at Mt.Aso, Japan. \nSpecial Issue on the Asia-Pacific Symposium on Applied Electromagnetics and Mechanics (APSAEM2014