The Texas Electronics, Inc. TB-2012M Barometric Pressure Sensor uses an active solid-state device to sense barometric pressure. Self-contained electronics provide a regulated voltage to the solid-state sensor and amplification for the signal output. The unit's range of 26" to 32" or 878 mb to 1080 mb of mercury allows it to be used at elevations up to 1800 feet or 548.64 meters above sea level. The unit is temperature compensated from -18° to +50°C. if elevations above 1800 feet or 548.64 meters are required, contact the factory for higher elevation calibration.