| 摘要 |
PURPOSE:To drastically raise the noise elimination accuracy by providing refer ence coils fewer than pickup coils and a means for calculating overall magnetic noise by interporation. CONSTITUTION:Only in the four corners of a measuring surface put by a multitude of pickup coils 21 and in the center, reference coils 20 are put. An interporation processor 24 obtains an interporation correlation based on the outputs R1 to R5 of the coils 20 and forms interporation data C1 to Cn. An environmental noise elimination calculator 23 subtracts corresponding interporation values C1 to Cn from each output value B1 to Bn. An interface 22 performs A/D conversion. By this, noise elimination accuracy is drastically raised compared with the case using a reference coil. And it is not necessary to equalize the number of reference coil channels to that of the pickup coil channels and therefore, even with the progress of multichannelling the size of the magnetic measurement device is suppressed within a certain size. |
