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CGA100 Combustible Gas Analyser

The CGA100 is a calorimeter designed to monitor the quality of natural gas and other combustible gases by determining the CARI (Combustion Air Requirement Index), Wobbe Index (WI) or Heating Value (calorific value) of the gas, depending on the application.

CGA100 Combustible Gas Analyser
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The instrument mixes air and process gas in a temperature controlled enclosure. The mixture then enters a catalytic combustion chamber where it is burnt with the aim of complete combustion of the sample with only residual oxygen remaining. This residual oxygen is measured by a zirconium dioxide cell, with the residual oxygen measurement being directly related to the heating characteristics of the gas.

A programmable controller receives all measured values and safety status and calculates the CARI, the Wobbe index and Heating Value with the optional Module. The controller is also able to initiate automatic calibration cycles with malfunction detection (out of specification) related to the calibration.


  • Continuous measurement
  • Fast Response
  • High Accuracy and repeatability
  • Automatic calibration in 2 points minimum
  • Minimal maintenance


  • Furnace control for: steel, glass, ceramic, lime….
  • Energy calculation
  • Recovery gases for steel industry
  • Fuel gases for refineries
  • Biogas
  • Control gas blending
Accuracy : +/-0.5% Full scale
Repeatability : +/-0.5% of measured value
Drift : less than 0.1% of reading per month
Response time : T90 < 30 s
Density cell : Continuous measurement
range : 0 to 3
Display : Touch sensitive display (All functions)
Units : kWh/Nm3, MJ/Nm3, TH/Nm3, BTU,
Analogue   Corresponding to user selectable parameter
outputs : (CARI and Wobbe Index)
    Up to 4 analogue outputs Heating value and density (in option)
Alarm outputs : Corresponding to user selectable alarm: Low and high alarm, Air/sample pressure alarm, calibration gas pressure alarm, Calibration active alarm, Calibration error, General default alarm…
Calibration : Manual or Automatic in 2 points
    (Up to 4 points depending on the span)
Communication : MODBUS RS485 (in option)
    Some data storing facilities (Alarms, calibration results, configuration…) visualization on display or RS485 transfer
Power supply : 230 VAC, 50Hz/ 115 VAC, 50/60 Hz / 400
Sample flow : 50 l/h
pressure : >1.5 to 3 bars relative
air flow : 150 l/h

Measuring ranges:
CARI span in 15 max 0 -25 range Wobbe Index span in 50 MJ/Nm3 max 0-100 MJ /Nm3range Heating value span in 50 MJ/Nm3 max 0-126 MJ /Nm3range (in option with density cell) (Span extension available in option with internal mix air/gas ratio commutation)