A system and method for monitoring the effectiveness of a coating on a substrate surface and indicating the failure of the coating to adequately protect the surface from corrosion, degradation, and the like. The system includes a sensor array positioned in contact with the coating utilizing a number of sensor electrodes connected to a single integrated circuit or a number of separate individual sensor circuits. The electrodes of the sensor array make measurements of the electrochemical impedance characteristics of the coating and provide such data by way of telemetry to a data interrogation device that is periodically be placed in proximity to the sensor array. The interrogation device may serve to both power the sensor array and trigger it to acquire data. A nominal parameter N′, which is the product of the impedance magnitude and the phase angle, is utilized as a direct indication of the resistance and capacitance characteristics of the coating and therefore a direct indication of the coatings effectiveness.