| 摘要 |
PROBLEM TO BE SOLVED: To improve the measurement accuracy of the rotation frequency of a sample tube for NMR measurement and accurately control the rotation of the sample tube.SOLUTION: An operation unit 18 sets a gate period Tg for a rotation pulse string signal 110 generated with the rotation of the sample tube 40, and acquires a count value Ns by counting the number of rotation pulses in the gate period Tg. The operation unit 18 has a function of using a high-speed clock signal 120 to determine the time difference between the gate period Tg and the rotation pulse string signal 110 occurring on the start side and end side of the gate period Tg, and correcting the length of the gate period Tg on the basis of the time difference. On the basis of the length of the gate period Tg after the correction, the rotation speed of the sample tube 40 is determined. A control unit 20 controls the rotation of the sample tube 40 so that the rotation speed determined by the operation unit 18 coincides with set rotation speed. |
