9800 Calorimeter



The COSA 9800 calorimeter measures Wobbe Index, BTU/Heating Value and CARI (Combustion Air Requirement Index).  Key advantages of this calorimeter are its insensitivity to changes in ambient temperature, a very fast response with the ability to measure gases with BTU values down to zero and the measurement of the Combustion Air Requirement Index besides Wobbe Index and Heating Value.

Our COSA 9800 calorimeter is a fast response, injection-style zero-hydrocarbon emissions calorimeter.  It can provide direct measurement of Calorific Heating Value and BTU with a measurement range 0-3000 BTU/scfh.  A real advantage with our COSA 9800 calorimeter is that it can handle high Sulfur concentrations with an H2 measurement option.

  • Industrial PLC System, Touchscreen HMI
  • High Temperature Combustion
  • Flameless / No Flameouts
  • Built for Indoor, Outdoor, Dirty, and Corrosive Environment
  • Precise Measurement of Air Fuel Ratio

Additional Features

  • Compact, sturdy O2 Cell is designed to be cost-effective, and for ease of maintenance and service
  • Internal sample system up to 50°C with options to 100°C or 150°C
  • Full measurement range 0-3000 BTU/SCFH without the need of a specific gravity meter


The COSA Xentaur 9800 calorimeter Wobbe Index measurement is based on the analysis of the oxygen content in the flue gas after combustion of the sample.  A continuous gas sample is mixed with dry air at a precisely maintained constant ration, which depends on the BTU range of the gas to be measured. The fuel air mixture is oxidized in a combustion furnace in the presence of a catalyst at 800’C, and the oxygen concentration of the combusted sample is measured by a zirconia oxide cell.  The residual oxygen provides an accurate measurement for the Combustion Air Requirement (CARI) of the sample gas, which can be correlated accurately to the Wobbe Index of the gas.

Key advantages to using our measuring principle, based on the Residual Oxygen Measurement Method, are its insensitivity to changes in ambient temperature, very fast response times with the ability to measure BTU values down to zero.  A small constant volume of sample gas is injected into a continuous flow of combustion air with each measurement cycle, providing a precisely maintained fuel/air ratio profile. The fuel air mixture is oxidized in the combustion furnace at 1000°C, and the residual oxygen concentration of the combustion sample is measured by a zirconia oxide sensor. The residual oxygen provides an accurate method of measuring Heating Value with optional measurement of Wobbe Index correlated to Specific Gravity of the sample gas. Higher temperature reduces maintenance of the instrument; varying temperature up to 1000°C.

  • High Accuracy
  • Fast Response
  • Large Measurement Range
  • Measures Low BTU Gases
  • Low Maintenance
  • Flameless / No Flameouts
  • Measures Wobbe and CARI
  • EPA 40CFR63.670(j) Compliant
  • Direct Measurement Method (ASTM D-4891 Compliant)
  • Gross or Net Heating Values


  • No moving parts 
  • Low maintenance requirements
  • Can operate unattended for several months
  • All compartments are easily accessible through separate doors on the front side of the enclosure

Fast Zero-Emissions Hydrocarbon Calorimeter

Process Insights)COSA 9800 Calorimeter


  • Air Blending Applications
  • Coke Oven Gas
  • Combustion Control
  • Custody Transfer
  • Flare Stack Control
  • Flare Stack Monitoring
  • Fuel Gas Optimization (boilers using process off-gas)
  • Furnace Gas
  • Gas Turbine Efficiency Control (fuel mixing skid)
  • Hydrogen Applications
  • Natural Gas Blending (Biofuel addition)
  • Natural Gas Blending (Liquefied Natural Gas)
  • Natural Gas Custody Transfer
  • Steam Generation
  • Turbine Control
  • VOC and Storage


Americas +1 713.947.9591
EMEA +49 69 20436910
China/APAC +86 400 086 0106


Analyzer Construction

  • Housed in a painted stainless steel NEMA4X (IP66) cabinet with the dimensions 41” x 41” x 16” suitable for outdoor installations without additional temperature-controlled shelter
  • For extreme climate conditions, the standard operating temperature range can be extended with the addition of a cabinet heater and/or vortex cooler
  • Cabinet is suitable for wall mounting or rack mounting

The analyzer cabinet has three compartments:

  1. The Gas Mixing Compartment: Contains sample condition and the gas mixing system. Components in this compartment are intrinsically safe. The gas mixing compartment can optionally be heated to avoid condensation of heavier gas constituents.
  2. The Electronics Compartment: Contains the industrial PC based controller, which performs all instrument control functions and calculations. Results are available through isolated analog outputs and an LCD, which is visible through a cabinet window and displays residual O2 in %, cell voltage in mV, Wobbe Index and Calorific Heating Value (optionally) in BTU/SCF or MJ/Nm3, relative density (optional), and CARI (Combustion Air Requirement Index).
  3. The Combustion Furnace Compartment: Contains the combustion furnace with the zirconia oxide sensor. The exhaust gas is vented and drained. The electronics compartment and combustion furnace compartment can optionally be purged for Class 1 Div 2 or Class 1 Div 1 applications.

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