Calorimeter Measurement Principle (Residual Oxygen Measurement)
The COSA 9610™ Wobbe Index Meter's measuring principle 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 of this method 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.
The COSA 9610™ is 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 of the COSA 9610™ can be extended with the addition of a cabinet heater and/or vortex cooler. The cabinet is suitable for wall mounting or rack mounting.
The analyzer cabinet has three compartments:
The COSA 9610™ has no moving parts and consequently, maintenance requirements are low. With the use of proper sample conditioning, the COSA 9610™ can operate unattended for several months. All compartments are easily accessible through separate doors on the front side of the enclosure.
The COSA 9610™ Wobbe Index Meter has superseded previous models of calorimeters such as the COSA 9600™ and COSA CW95.