Lu Tao, Li Zhengjia, Xia Danqing, He Kaihua, Zhang Guangyong
School of Mathematics and Physics, China University of Geosciences, Wuhan 430074, People's Republic of China.
Rev Sci Instrum. 2009 Mar;80(3):033104. doi: 10.1063/1.3093808.
It is demonstrated that an asymmetric Fabry-Pérot fiber-optic pressure sensor is capable to precisely measure liquid levels. They are directly proportional to pressures that can modulate cavity length of Fabry-Pérot cavity. As a result, the sensor can operate over a linear region of an interference fringe that enables liquid-levels interrogation by measuring the reflected intensity. Experimental results show the resolving power of 0.4 mm, sensitivity of 2.4 mV/mm, and precision of 1 mm over range of 2.3 m (water) can be achieved. The sensor can measure liquid levels accurately, continuously, and automatically in flammable and explosive circumstances.
结果表明，一种非对称法布里-珀罗光纤压力传感器能够精确测量液位。液位与可调节法布里-珀罗腔腔长的压力成正比。因此，该传感器可在干涉条纹的线性区域内工作，通过测量反射强度来实现液位检测。实验结果表明，在2.3米（水）的量程范围内，该传感器的分辨率可达0.4毫米，灵敏度为2.4毫伏/毫米，精度为1毫米。该传感器能够在易燃易爆环境中准确、连续且自动地测量液位。
