In this study, a corrosion monitoring sensor (CMS) was fabricated by the screen-printing technique. The impedance of the CMS was measured by a two electrode system. A 15 mg cm-2 NaCl was dispersal on the CMS before the measurement. The temperature and relative humidity were kept at 25 ℃ and 90 % in a thermostatic chamber during the measurement. The impedance of CMS was measured during wet and dry conditions due to the deliquescence of NaCl. The impedance measurement was carried out for 17.5 hours. The DC voltage was open circuit voltage. The voltage amplitude was 10 mV. The frequency range of the impedance was from 10 mHz to 10 kHz. After the impedance measurement, the CMS was dried at 60 ℃ . In addition, the impedance of CMS was also measured at room temperature after drying.
The impedance of CMS was measured every 2.5 h, indicating that a loop related to the electrode/solution interface was observed on the Nyquist plane. The magnitude of impedance at each time was discussed with the generation of the water film on the CMS during measurements.
 S. Motoda, Y. Suzuki, T. Shinohara, Y. Kojima, S. Tujikawa, W. Oshilawa, S. Itomura, T. Fukushima, S. Izumo, Zairyo-to-Kankyo, 43,550 (1994).
 I. Shitanda, A. Okumra, M. Itagaki, K. Watanabe, Y. Asano, Sensors and Actuators B: Chemical ,139, 292 (2009).