公开(公告)号：US4524322A

公开(公告)日：1985-06-18

申请号：US442497

申请日：1982-11-18

Applicant: Lloyd C. Bobb

Inventor： Lloyd C. Bobb

IPC: G01R15/24 ,  G01R29/08 ,  G01R29/12 ,  G01R31/02 ,  G01R31/00

CPC classification number: G01R29/12 ,  G01R15/248 ,  G01R29/0885

Abstract: A fiber optic sensor system and associated technique is disclosed for measuring an electric field wherein a sensor arm of optical fiber cable is wound about a core member of piezoelectric material. A reference arm of optical fiber cable substantially equal in optical path length to the sensor arm is isolated and connected in parallel to the sensor arm so that coherent light generated by a single mode laser source may be split through the fiber-optic arms and recombined after passage therethrough for phase comparison. When subjected to a local electric field, the core member of piezoelectric material varies in dimensions and thereby causes a change in the strain in the optical fiber cable of the sensor arm. Relative phase changes in the coherent light caused by the resulting optical path length change of the strained sensor arm are detected by a passive homodyne demodulator and determinative of the value of the local electric field. A vane-type shield is adapted to be rotated about the core member for periodically reducing the local electric field to near zero thereby providing a reference level for field measurement.

Abstract translation: 公开了一种用于测量电场的光纤传感器系统和相关技术，其中光纤电缆的传感器臂缠绕在压电材料的芯部件上。 光传感器臂的光路长度基本相等的参考臂与传感器臂平行隔离并连接，使得由单模激光源产生的相干光可以通过光纤臂分裂并重新组合 通过其进行相位比较。 当经受局部电场时，压电材料的芯构件的尺寸变化，从而导致传感器臂的光缆中的应变变化。 由应变传感器臂产生的光程长度变化引起的相干光的相对相位变化由被动零差解调器检测，并确定局部电场的值。 叶片式护罩适于围绕芯构件旋转，以便将局部电场周期性地减小到接近零，从而为现场测量提供参考水平。