The MAC125 Moisture Analyzer is a major advancement in the measurement of absolute humidity. The measurement process is solid state. No chemicals, compressed air, wet bulb techniques, optics or mirrors are used. The probe is protected from particulates by a 10 micron ceramic filter element, that is cleanable and replaceable. The measurement process uses a proprietary sensor which responds to the partial pressure of water vapor. The total pressure is also measured, and the moisture level is calculated from the ratio of the pressures. The MAC125 is the latest generation of Absolute Humidity Transmitter from MAC Instruments. The MAC125 and its predecessors are providing accurate, reliable, high temperature humidity measurement in many difficult industrial applications throughout the world, since 1990.