Model M90XP

Carbon Dioxide Monitor

Dual-Beam NDIR Technology

The Model M90XP and M90XP-ppm are designed to monitor ppm and percent level CO2 concentrations in natural gas and biogas applications. An infrared, dual-beam technology is incorporated into the design of the instrument. The M90XP and M90XP-ppm can be included as an additional measurement with other Envent analyzers, or can be offered as a stand-alone analyzer with an integrated sample conditioning system.


  • Features
    • Class I, Division 1
    • Dual-Beam NDIR Technology.
    • Long-term stability.
    • Low power consumption (2 watts).
    • Dual alarm outputs.
    • 4-20 mA output.
    • RS-232 and RS-485 Modbus communications.
    • Two Adjustable set point control relays.
    • Ppm and % level sensors available. 
  • Downloads
  • Certification
  • Applications
    • CO2 is measured routinely in natural gas for product quality and process control purposes. Common ranges are from 0-5% for sales gas and up to 0-30% for inlet CO2 concentration.
    • Gas plant Inlet.
    • Certain H2S-removal chemical processes can be fine-tuned by CO2 slipstreaming.
    • Quantify CO2 as a combustion by-product.
    • Biogas applications
  • Specifications
    Electrical classification Class I, Div1 Groups B, C & D
    Operating Principle Dual-beam, non-dispersive infrared (NDIR).
    Detector Sapphire window with glass frit seal
    Sensing Cell Proof Pressure (Sample cell only) 2 PSI (13.8 KPa) gauge pressure
    Measurement Range 0-5000ppm; 0–20% or 0-100% CO2; Custom ranges available
    Repeatability ± 0.1 % CO2
    Drift Less than 2.5% of reading/year
    Accuracy ± 3% of reading or 0.1% CO2 at cal temperature,
    ± 5% of reading or 0.1% CO2 over full operating temperature range.
    Warm U Time Less than 5 minutes
    Operating Humidity Sensing Cell: 0–100% RH (non-condensing).
    Electronics: 0 – 90% RH (non-condensing).
    Storage Temperature -20 to 60°C (-4 to 140°F).
    Storage Humidity 0–90% RH (non condensing).
    Analog Output Isolated 4–20 mA
    Digital Interface RS-485 & RS-232
    Operating Power 24 VDC at 2 Watts standard.
    12 VDC, 120/240 VAC optional
    Source Life 10 years minimum
    Alarm Outputs 2 solid state drivers 2 Amp, 30 VDC maximum
    Standard Sample System Inlet filter (1500psig/103bar max).
    SS single stage regulator (3000psig/207bar max).
    Flow meter (100psig/6.9bar max).

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