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MAC 125 Continuous Moisture Analyzer

MAC 125 Continuous Moisture Analyzer

The MAC125 high temperature moisture analyzer is capable of measuring absolute humidity in almost any temperature. The measurement process uses no chemicals, compressed air, wet bulb techniques, optics, or mirrors.

SKU: MAC125 Category:


The probe is protected from particulates by a 10 micron stainless steel sintered filter element that is cleanable and replaceable. The measurement process is patented and 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 transmitters from MAC Instruments. The MAC125 and its predecessors have provided accurate, reliable, high-temperature humidity measurement in many difficult industrial applications throughout the world since 1990.


  • Calculates percent moisture by volume or humidity ratio (mixing ratio) (lb water vapor/lb dry air) (g water vapor / g dry air) and dew point available
  • Mounts directly to stacks, ducts, flues, furnaces, etc.
  • Digital display option
  • Choose from 5 moisture ranges
  • Jumper Selectable Scales
  • Nema 4X / IP53 waterproof design
  • Severe duty industrial construction
  • Patented process
  • In-situ measurement
  • Standard signal outputs
  • Automatic altitude/pressure compensation
  • Digital display option
  • Filter blow back option
  • Case heater option
  • Case cool option



  • Temperature range:
    • 40°F/4°C to 1200°F requires a special mounting tube
  • Pressure range:
    • 1 atmosphere ±5 PSI/35kP
  • Accuracy:
    • ±1% of %Mv full scale
  • Linearity:
    • ±1% of %Mv full scale
  • Hysteresis:
    • ±1% of %Mv full scale
  • Response time:
    • 60 seconds or less reach 90% of final value
      (with high-speed pump option)
  • Analog output:
    • 4-20 mA, 0-20 mA (user-selectable)
  • Power requirements:
    • Model 120V – 100V-132V 50/60 Hz @ 3A max
    • Model 230V – 200V-250V 50/60 Hz @ 1.5A max