A Novel Passive Wireless Sensing Method for Concrete Chloride Ion Concentration Monitoring

Abstract

In this paper, a novel approach for concrete chloride ion concentration measuring based on passive and wireless sensor tag is proposed. The chloride ion sensor based on RFID communication protocol is consisting of an energy harvesting and management circuit, a low dropout voltage regulator, a MCU, a RFID tag chip and a pair of electrodes. The proposed sensor harvests energy radiated by the RFID reader to power its circuitry. To improve the stability of power supply, a three-stage boost rectifier is customized to rectify the harvested power into dc power and step-up the voltage. Since the measured data is wirelessly transmitted, it contains miscellaneous noises which would decrease the accuracy of measuring. Thus, in this paper, the wavelet denoising method is adopted to denoise the raw data. Besides, a monitoring software is developed to display the measurement results in real-time. The measurement results indicate that the proposed passive sensor tag can achieve a reliable communication distance of 16.3 m and can reliably measure the chloride ion concentration in concrete.

Sensing Characteristics of Arrayed Flexible Chloride Sensor Based on the XBee Wireless Sensing System

“…The sterilization capabilities were from free chlorine. The free chlorine were contained the hypochlorous acid (HClO) and hypochlorite ion (ClO − ) concentrations [7,34]. We used the wireless sensing system to investigate the sensitivity and linearity for different NaClO solutions from 10 -6 M to 1 M. From Figure 9, the average sensitivity and linearity were 28.92 mV/pCl and 0.982, respectively, and it could be found the flexible…”

“…The sensitivity comparisons of the chloride ion sensing devices were shown in Table 1. The wireless transmission technology was obtained the RFID [7], Bluetooth [10]. S. Zhou et al [7] prepare the wireless chloride ion sensor.…”

“…The wireless transmission technology was obtained the RFID [7], Bluetooth [10]. S. Zhou et al [7] prepare the wireless chloride ion sensor. The sensitivity of wireless chloride ion sensor was 47.83 mV/pCl.…”

“…Many researchers detected different ions and obtained experiment data easier with wireless sensing system [5][6][7][8][9][10][11][12][13][14][15]. The wireless sensing system had been applied to different fields, such as chloride ion detection [5][6][7][8][9][10][11][12][13][14][15][16], hydrogen ion detection [17][18][19][20][21][22][23], glucose detection [23][24][25] and lactate detection [25].…”

“…The hypochlorite ions sensor integrated with wireless transmission system, and investigated the hypochlorite ion concentration variations, and the hypochlorite ion sensor included the layer of polyurethane and alumina on the magnetically-soft ferromagnetic ribbon. S. Zhou et al [7] used the Ag/AgCl electrode, reference electrode and radio-frequency identification (RFID) communication protocol to measure and investigate the chloride ion concentrations in the concrete. N. Harris et al [8] used the screen printed technology to prepare the low cost robust chloride ion sensor.…”