Multigas Probe For methane, carbon dioxide, and humidity measurement

Methane, carbon dioxide, and humidity (or dew point) may all be measured with the Vaisala CARBOCAP® MGP261, a compact in situ multigas probe that provides a comprehensive view of the composition of biogas and landfill gas without the need for separate instruments. Its revolutionary CARBOCAP® infrared sensor provides consistent, repeatable readings without the need for calibration gases, and it installs straight into the process pipeline without the need for sample treatment or moisture removal. Anaerobic digestion and landfill gas monitoring, biogas treatment using activated carbon filters, and CHP engine feed gas monitoring are common uses. With encapsulated electronics and 316L stainless steel/PTFE construction chosen for resistance to hydrogen sulphide and other extreme process conditions, the probe is Ex-certified for Zone 0 (process-inserted parts) and Zone 1 (external parts).

Key specifications and features:

• Triple CARBOCAP® infrared sensors measuring methane (0–100 vol-%), carbon dioxide (0–100 vol-%), and water vapor (0–25 vol-%, or dew point −10 to +60 °C)
• Accuracy of ±1 to ±2 vol-% for CH₄ and CO₂ depending on range, and ±0.5 vol-% for water vapor (0–25 vol-%)
• No calibration gases needed; long-term stability of ±2 vol-%/year across all three gases
• Response time (T90) of 90 seconds; 30-second start-up and 2-minute warm-up
• Ex-certified for Zone 0 (inserted into process) and Zone 1 (outside process) — ATEX, IECEx, cMETus, CML, UKEX, and KCs approvals
• Operating/process temperature range of −40 to +60 °C (−40 to +140 °F), process pressure range of −500 to +500 hPa, and flow range up to 20 m/s
• Corrosion-resistant AISI316L stainless steel and PPS probe body with sintered PTFE filter, rated IP66
• Standalone operation via digital Modbus RTU over RS-485 or 3 scalable, isolated 4–20 mA analog outputs
• Optional 4–20 mA analog input for an external pressure or temperature sensor
• Compatible with Vaisala Insight PC software for configuration and diagnostics
• 18–30 V DC operating voltage, typical power consumption of 3 W (6 W max)