An impedance response-based corrosion sensorwas developed with precision screen-printing method. The sensor has two symmetrical zigzag conducting parts. One part of sensor covered with resist ink is a reference part serving as the standard to normalize an impedance response. Impedance measurements were performed by dropping of NaCl solution on the sensor to simulate dew condensation. The Nyquist plot of impedance converged on the real number axis in the dry condition and shows a capacitive semicircle in wet condition. Further, it was shown that the diameter of the capacitive semicircle was proportional to the wet area ratio of the sensor surface. (C) 2018 The Electrochemical Society.