Design of small range and high precision fiber Bragg grating static level

To solve the problem of instability and damage caused by non-uniform settlement of large crude oil storage tank foundation which is characterized by centralized arrangement, inflammable, explosive and toxic medium, a small range and high precision fiber Bragg grating static level was developed to realize the problem of high precision monitoring of uneven settlement of crude oil storage tank foundation. The theoretical sensing model of fiber Bragg grating static level was derived, and the main structure of the fiber Bragg grating manager level was designed, which is composed of a metal float, a force transmission rod, a lever, a pressure measuring fiber Bragg grating, and a temperature measuring fiber Bragg grating. The static characteristics and error of the small range fiber Bragg grating static level were analyzed by experiments. The results show that the average sensitivity of fiber Bragg grating static level is 23.88 pm/mm, the linearity error is 0.4%, the hysteresis error is 2.16%, the repeatability error is 3.78%, and the static error is 4.37% in the measuring range of 50mm. The small range high-precision fiber Bragg grating static level developed meets the requirements for health monitoring of uneven settlement of large crude oil storage tank foundations, and is also suitable for settlement monitoring in other harsh environments. The small range and high precision fiber Bragg grating static level developed meets the requirements of the health monitoring for the non-uniform settlement of large crude oil storage tank foundation, and is suitable for the settlement monitoring in other harsh environments.