Development of a new technique of magnetic survey based on vector field measurement

研制了一种新型仪器“三分量磁通门梯度仪”。该仪器可以对地磁场进行全矢量测量。该梯度计由两个三分量磁通门磁强计组成，沿垂直线相距50cm。磁通门传感器采用坡莫合金制成的环形磁芯。由于环形磁芯不泄漏磁通量，相邻传感器之间的干扰可以最小化。该梯度仪从上磁强计输出地球场Bx、By和Bz及其梯度dBx、dBy和dBz。梯度的分辨率为1nT。地球磁场数据可用作罗盘数据。控制器可以在内存中记录4000点数据，并通过RS-232C接口将这些数据发送到计算机。利用该梯度仪在宫城县惠比寿森墓、根岸遗址（福岛县）、乌托窑遗址（福岛县）、太尻遗址（郡马县）、Saruta窑遗址（郡马县）、O-terayama洞穴（千叶县）、石形墓（静冈县）、O-chiba关寺遗址（静冈县）、鸟比山1号墓（岐阜县）、inizuka墓（京都县）、Kaibukiyama墓（大阪县）、圭矢冢冢（兵库县）、南海市遗址（兵库县）、东山冢（兵库县）、岩山冢（福冈县）、西原洞冢（宫崎县）等。通过这些实验，证明了该梯度仪比传统仪器更有效，并开发了利用三分量梯度仪进行磁测量的程序。

A new instrument, "Three-Component Fluxgate Gradiometer", was Developed. This instrument can make full vector measurements of Earth magnetic field. This gradiometer is composed of two three-component fluxgate magnetometers placed 50cm apart along the vertical line. A ring core made of permalloy is used on the fluxgate sensor. Since the ring core does not leak out magnetic flux, the interference between adjacent sensors can be minimized. This gradiometer outputs the Earth field, Bx, By and Bz from the upper magnetometer, and its gradient dBx, dBy and dBz. The resolution of the gradient in 1nT.The data of the Earth's field can be used as compass data. The controller can record 4.000-point data in the memory and send these sata to a computer through its RS-232C interface.A lot of sxperiments of field survey using this gradiometer were carried out at Ebisu-mori mounded tomb (Miyagi Pref.), Negishi site (Fukushima Pref.), Ooto Kiln site (Fukushima Pref.), Tajiri site (Gun-ma Pref.), Saruta Kiln site (Gun-ma pref.), O-terayama cave (Chiba Pref.), Ishinogata mounded tomb (Shizuoka Pref.), O-chiba pass temple site (Shizuoka Pref.), Zoubisan No.1 mounded tomb (Gifu Pref.), Inarizuka mounded tomb (Kyoto Pref.), Kaibukiyama mounded tomb (Osaka Pref.), Gyoujyazuka mounded tomb (Hyogo Pref.), Nanukaichi site (Hyogo Pref.), Higashiyama mounded tomb (Hyogo Pref.), Iwatoyama mounded tomb (Fukuoka Pref.), tunnel tombs in Saitobaru (Miyazaki Pref.) and so on.Through these experiments, it was proved that this gradiometer was more available than conventional instruments, and the procedure for magnetic survey using the three-component gradiometer has been also developed.