The ECM™ is a multiparameter monitoring system providing constant surveillance of the environment and rapid detection of any deterioration that could result in damage to expensive equipment and valuable assets. Early detection of humid, high temperature, or corrosive conditions will permit corrective action to be taken before substantial damage occurs to sensitive computer and instrumention systems or electrical equipment. The system measures humidity, temperature, and the corrosive attack on two replaceable thin-film sensors. The corrosion rate is shown by indicator lights that correspond to the ISA classification of environments (G1 through GX) for copper and silver. Analog and/or digital outputs of corrosion, humidity and temperature information provides remote alarming, display and recording. The information may also be stored in the on-board datalogger, and accessed via PC software. The system can also be used as a high-sensitivity corrosion monitor for special applications.