| 摘要 |
PURPOSE: To prevent occurrence of a voltage error at a squid electronic circuit due to a calibration error of a magnetic gradient meter by providing two calibration coils of the same ampere turn numbers in a reverse magnetic field, with the same distance from a magnetic field gradient meter coil in axis-line symmetry. CONSTITUTION: The primary axis-direction gradient meters are assigned with a gap in axis direction, and provided with two coils which, electrically connected in series, have a parallel coil surface. The lower side coil which is subject to the measurement magnetic field is a pick-up coil 1, and the upper side coil is a compensation coil 2, and a constant magnetic field penetrating bath coils is compensated in a coil wound in the reverse direction. Calibration coils 4 and 5 are assigned with the same distance I from coil surfaces which, electrically connected in series, have the same turn numbers in axis-line symmetry and in parallel, with their windings in reverse direction. With the coils 4 and 5, the magnetic field generated at the coils 1 and 2 are calculated in numeric value, and in order to decide a calibration factor, division is performed at an output end of a subordinate squid electronic circuit with a measurement voltage. |
