| 摘要 |
PURPOSE:To provide a surface potential sensor in which simplification and size reduction in a circuit can be carried out and dependence of a mounting distance is eliminated. CONSTITUTION:A surface potential sensor is provided with a piezoelectric tuning fork 30, a sensor part using a detector electrode 4, a tuning fork driving circuit 15, a preamplifier circuit 12 connected to the detector electrode 4 of the sensor part 5, an amplifier circuit 13, a synchronous detector circuit 17, an integration circuit 18, and a high voltage amplifier circuit 19, and primary side of the piezoelectric tuning fork 30, the detector electrode 4, the preamplifier circuit 12, the amplifier circuit 13, the synchronous detector circuit 17, the integrating circuit 18, and the high voltage amplifier circuit 19, the secondary side of the power circuit 21 using a transformer, and its shield are floated from the power source, while the generation voltage of the high voltage amplifier circuit 19 is returned at least to a compsn ground of the sensor part 5. In this way, the mounting distance of the sensor part is free from dependence and a mounting precision can be eased while simplification and size reduction in the circuit are achieved. |
