In order to detect the liquid leak, many researchers present different methods. However, traditional detection methods are
electrical methods, which are costly and unsafe. In this study, we present a LPG sensing system for leak detection of oil
storage tanks. Since LPG is sensitive to external refractive index changes LPGs can be used as sensors to detect oil leak.
In this paper, a theoretical analysis of the optimal package diameter of fiber Bragg grating (FBG) pressure sensors is
presented. We use the theory of elastic to analyze the relation between the pressure sensitivity and the package diameter
of FBG with d ifferent materials, structures. Then we can get the optimal package diameter of FBG pressure sensor for a
certain package structure and material. Through the following experiments, it can be proved that the theoretical analysis
is correct. This analysis could not only significantly enhance the pressure sensitivity, but also provide the optimal
package diameter of FBG for the practical applications.
In self-powered wireless sensor nodes, the efficiency for environmental energy harvesting, storage and
management determines the lifetime and environmental adaptability of the sensor nodes. However, the method of
improving output efficiency for traditional photovoltaic power generation is not suitable for a solar micro-power
system due to the special requirements for its application. This paper presents a solar micro-power system
designed for a solar self-powered wireless sensor node. The Maximum Power Point Tracking (MPPT) of solar
cells and energy storage are realized by the hybrid energy storage structure and "window" control. Meanwhile, the
mathematical model of energy harvesting, storing and management is formulated. In the novel system, the output
conversion efficiency of solar cells is 12%.