Bridge health detection and monitoring Bridge structural health monitoring (SHM) is an active defense method based on sensors, which can make up for the very important safety performance of current structures. It is a reliable and cheap method to put sensor networks in bridges, buildings and airplanes and use sensors for SHM, which can detect the formation of defects in the first time. This kind of network can report the defects in key structures to maintenance personnel in advance, thus avoiding catastrophic accidents. The wireless sensor network technology of granary temperature and humidity monitoring is the most widely used in the field of granary temperature and humidity monitoring, because there are many measuring points of granary temperature and humidity, which are widely distributed, and the use of crisscross signal lines will reduce the fire safety factor. The application of wireless sensor network technology has the characteristics of low power consumption, low cost, simple wiring, convenient installation, easy networking, convenient management and maintenance. Monitoring of concrete pouring temperature In the process of concrete construction, the digital temperature sensor is installed in the metal sleeve with good thermal conductivity, which can ensure the sensor to respond quickly to the temperature change of concrete. Each temperature measuring metal pipe is connected with a wireless temperature node, and the wireless temperature node of the whole site is transmitted to the construction monitoring center through a wireless network, so that it is not necessary to lay a long cable on the construction site, which is convenient to install and lay, and can effectively solve the problem of low survival rate of temperature measuring points caused by cable damage by construction personnel. Earthquake monitoring uses a sensor network composed of a large number of interconnected micro-sensor nodes, which can continuously collect high-precision data in different environments. Using low-power wireless communication module and wireless communication protocol can prolong the life of sensor network for a long time. And the practicability of the sensor network is ensured. Compared with traditional networks, the most obvious characteristics of wireless sensor networks can be summarized in six words: "self-organization and self-healing". These characteristics enable wireless sensor networks to adapt to the complex and changeable environment and monitor the harsh environmental areas that are difficult for human beings to reach. BEETECH wireless sensor network nodes are small in size and do not need on-site power supply, which is very convenient for flexible deployment, monitoring and prediction of geological disasters in emergency. Building vibration detection the cantilever part of the building will not exceed the comfort requirement because of the vibration caused by the nearby expressway and subway traffic; Through field measurement and data collection, the relationship between the vibration caused by highway and subway traffic and the cantilever vibration of the main building is verified. At the same time, the damping ratio of the first few modes of the main structure of the building under the condition of small amplitude pulsating vibration is obtained through modal analysis, which provides key data for the small amplitude dynamic analysis of the structure in the future. In this application, the high-precision acceleration sensor is used to capture the weak vibration of large structures, and is also suitable for the measurement of wind load and vehicle-induced pulse.