Abstract: The heating value of a sample gas is calculated by a microcontroller (12) from the heating value of a reference gas, and from flow ratios and power levels determined as the gas is combusted by a flameless combustion process. The combustible gas is mixed with a combustion supporting gas, such as air, and flowed to a body of material (26, 52) which is heated to a temperature sufficient for oxidation of the gas mixture. The size of spaces in a first embodiment of a heater device (9, 11, 25, 26) and in a second embodiment of a heater device (50) are limited to prevent formation of an open flame. In a preferred "lean mixture" embodiment, the gas-air mixture of the reference gas, and the gas-air mixture of the sample gas, respectively, are each adjusted until a selected power level of combustion at a temperature lower than the point of stoichiometric combustion is reached.

Abstract: The heating value of a sample gas is calculated by a microcontroller (12) from the heating value of a reference gas, and from an oxidation energy ratio determined as the gas is combusted by a flameless combustion process. The combustible gas is mixed with a combustion supporting gas, such as air, in a volume chamber (4) and injected into a combustion device (8, 50) in which a body of inert material (26, 51, 53) is heated above the auto-ignition temperature of the gas mixture. The inert material (26, 51, 53) is arranged to have a void dimension that is small enough to prevent the formation of an open flame during combustion. The process is repeated with a sample gas. During the injection cycle, the microcontroller (12) receives signals which monitor the power of combustion. The microcontroller (12) calculates the heating value of the sample gas and generates an output signal to a visual display or other output device.

Abstract: The heating value of a sample gas is calculated by a microcontroller (12) from the heating value of a reference gas, and from flow ratios and power levels determined as the gas is combusted by a flameless combustion process. The combustible gas is mixed with a combustion supporting gas, such as air, and flowed to a body of material (26, 52) which is heated to a temperature sufficient for oxidation of the gas mixture. The size of spaces in a first embodiment of a heater device (9, 11, 25, 26) and in a second embodiment of a heater device (50) are limited to prevent formation of an open flame. In a preferred "lean mixture" embodiment, the gas-air mixture of the reference gas, and the gas-air mixture of the sample gas, respectively, are each adjusted until a selected power level of combustion at a temperature lower than the point of stoichiometric combustion is reached.

Abstract: The heating value of a sample gas is calculated by a microcontroller from the heating value of a reference gas, and from flow ratios determined as the gas is consumed by catalytic combustion. The combustible gas is mixed with a combustion supporting gas, such as air, and flowed to a catalytic apparatus. In one embodiment, a molar flow meter is connected in the supply line for the combustible gas to measure the molar flow rate of a reference gas and a sample gas. Molar flow rates of the reference gas and the sample gas are determined at maximum temperature of combustion of the gas. In a preferred embodiment, a valve chamber is charged with a gas to a predetermined pressure and then discharged. During the discharge cycle, the apparatus senses the maximum temperature of combustion which corresponds to the point of optimum fuel-to-air ratio for catalytic combustion.

Abstract: The heating value of a sample gas is calculated by a microcontroller (12) from the heating value of a reference gas, and from flow ratios determined as the gas is consumed by catalytic combustion. In a preferred embodiment, chambers (5, 14) of fixed volume are charged to a predetermined pressure with a reference gas and a sample gas, respectively, and flowed to the catalyst at variable, changing flow rates as pressure decays. During the discharge cycle, a pressure transducer (13) senses the decaying pressure and this information is input to the microcontroller (12), which computes molar flow rates and which also senses the power level of combustion through a bridge circuit (24) in the catalytic apparatus (8, 10). Based on a ratio of molar flow rates and a ratio of corresponding power levels, a heating value of the sample gas is calculated by the microcontroller (12) and output to a visual display or other output device.