| 摘要 |
PURPOSE:To reduce the change in brightness generated in a light source, by a method wherein a high frequency magnetic field is applied to an absorption cell for a definite period or is not applied thereto to alternately perform non- magnetic resonance operation and magnetic resonance operation and the measuring signals of both operations are set off by a differential amplifier. CONSTITUTION:The second sample holding circuit 17 almost continuously measures the change in the brightness of a lamp or absorbing cell when no magnetic resonance is generated and the first sample holding circuit 16 almost continuously measures the absorption signal at the time of magnetic resonance and the change in the brightness of a light source appearing in a state superposed to said signal. A differential amplifier 18 respectively inputs the output signals SIG, NOIS of the above mentioned first and second sample holding circuits, 16, 17 at the positive and negative input terminals thereof and sets off the detect signals observed at the times of magnetic resonance operation and non-magnetic resonance operation to reduce the change in the brightness of the light source superposed to the absorption signal at the time of magnetic resonance. |
