Development of AE monitoring system for detection of termite attack in wooden house at early stage

为早期检测木屋白蚁侵袭，研制了一种新型声发射监测系统。该系统由带有灵敏声发射传感器的便携式声发射探测器、连接探测器与互联网的接口单元以及用于系统控制、数据记录和分析的软件组成。声发射探测器是1999年课题研制的，具有放大、滤波、甄别、计数声发射事件的功能。包括：探测器与现场CPU之间的接口(称为事件适配器)、数据传输和控制装置以及现场CPU与中央控制CPU(或客户CEU)之间通过局域网或互联网或电话进行数据管理的程序。研究了传感器的性能和基于网络的数据传输系统。客户端可以通过PC或手持电话通过互联网访问服务器来获取数据。验证了木屋声发射连续监测系统的可行性。在研制过程中，利用常规声发射监测仪对木屋白蚁侵袭情况进行了监测。收集了仪器设计的基本信息。在调查中，通过目视检查检查了白蚁侵袭和其他生物退化情况。同时，利用声发射监测技术对白蚁危害进行了无损检测。通过声发射监测检测到白蚁的活动攻击。在室内试验中，研究了相对湿度与白蚁危害的关系。此外，还利用水泥稳定碎石(宝利石)的颗粒层对物理屏障中的声发射进行了监测，证实声发射是由颗粒之间的摩擦产生的，并对上述结果进行了全面的检验，并发表了最终报告。

A new AE monitoring system for the detection of termite attack in wooden house at an early stage was developed. The system consists of a portable AE detector with.an sensitive AE sensor, interface unit connecting the detector and the Internet and the software to System control and data logging and analysis. The AE detector (which was developed in the research project in 1999 has the functions; amplification, filtering and discrimination, counter to count AE events. The following devices involve; the interface between the detector and on-site CPU (called event adapter), the date transferring and control devices and the program for data management between on-site CPU and central control CPU (or Client CEU) using LAN or Internet, or telephones. The performance of the sensor and the data transferring system using internet was investigated. The client can derive the data by accessing to the server by internet through PC or handy phones. The feasibility of the continuous AE monitoring system for the wooden houses was confirmed.In the developing process, termite attack in wooden houses were detected, by using conventional AE rionitoring apparatuses. The basic information for the design of the apparatus was collected. In the survey, the termite attack and other biological deterioration was inspected by visual inspections. At the same time, non-destructive detection of termite attack using AE monitoring was also carried out. The active termite attack was detected by AE monitoring. In the laboratory tests, the relationships between the relative humidity and the termite infestation was investigated. AE monitoring in the physical barrier using particulates layer of crushed cement-stabilized sludge (Polynite) was also carried out, and it was confirmed, AE s were generated by the friction between the particulates.The above results were totally examined and the final reports was published.