基于无源RFID的混凝土湿度监测技术研究

Research on online monitoring technology for concrete humidity based on passive RFID

湿度控制是混凝土早龄期控制开裂的重要措施,由于混凝土是有损多相复合材料,文中首先具体分析了电磁波在混凝土中的损耗,确定了标签可正常工作的基本条件,然后介绍了一种用于混凝土湿度监测的无源射频识别(RFID)传感器标签,该RFID传感器标签是基于超高频(UHF)的EPC-2通信协议,且工作于无源模式下,并具体介绍了传感器结构、接口电路和整流模块。后期实验对所设计的湿度传感器进行了性能测试,结果显示该湿度传感器具有良好的线性度和稳定性。与传统湿度测量的结构相比,所设计的无源RFID湿度传感标签具有低成本以及低功耗的特点。

Humidity control is an important step to avoid cracking during concrete curing. Since the concrete is a lossy material, this paper analyzes the loss of electromagnetic wave transmitting in concrete and then achieves the working conditions of the radio frequency identification （RFID） sensor tag in concrete. Then a passive RFID sensor tag for concrete humidity monitoring is presented. The RFID sensor tag is based on EPC generation-2 ultra-high frequency （UHF） communication protocol and operates in passive mode, then the architecture of the proposed passive humidity sensor tag, interface circuit and rectifier are introduced in detail. The performance of the proposed sensor tag is tested in later experiment. The results show that the proposed humidity sensor achieves high linearity and stability. Compared with the traditional measurements, the proposed passive RFID sensor tag has advantages of low-cost and low power.