Dipartimento di Elettronica Informazione e Bioingegneria, Politecnico di Milano, 20133 Milano, Italy.
Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Milano, 20133 Milano, Italy.
Sensors (Basel). 2023 Mar 14;23(6):3117. doi: 10.3390/s23063117.
Water leakage is one of main problems of distribution infrastructures, reaching unacceptable peaks of 50% of water lost in old networks in several countries. In order to address this challenge, we present an impedance sensor able to detect small water leaks (below 1 L of released volume). The combination of real-time sensing and such a sensitivity allows for early warning and fast response. It relies on a set of robust longitudinal electrodes applied on the external surface of the pipe. The presence of water in the surrounding medium alters its impedance in a detectable way. We report detailed numerical simulations for the optimization of electrode geometry and sensing frequency (2 MHz), as well as the successful experimental proof in the laboratory of this approach for a pipe length of 45 cm. Moreover, we experimentally tested the dependence of the detected signal on the leak volume, temperature, and morphology of the soil. Finally, differential sensing is proposed and validated as a solution to reject drifts and spurious impedance variations due to environmental effects.
漏水是配水基础设施的主要问题之一，在一些国家，旧管网中损失的水量达到了令人无法接受的 50%峰值。为了解决这一挑战，我们提出了一种能够检测小漏水（释放量低于 1 升）的阻抗传感器。实时感应和如此高的灵敏度相结合，可以实现早期预警和快速响应。它依赖于一组应用在管道外表面的坚固纵向电极。周围介质中存在水会以可检测的方式改变其阻抗。我们报告了详细的数值模拟，以优化电极几何形状和感应频率（2MHz），并在实验室中成功验证了这种方法对 45 厘米长管道的效果。此外，我们还通过实验测试了检测信号对泄漏量、温度和土壤形态的依赖性。最后，提出并验证了差分感应作为一种解决方案，以消除由于环境影响而导致的漂移和虚假阻抗变化。
