| abstract |
A method and apparatus for real time gas analysis involving determining individual concentrations of fluid constituents in a mixture of known constituents by measuring properties of such mixture via sensor array and solving a set of equations relating the individual gas concentrations to the measured properties of the mixture, for the unknown individual gas concentrations or identities. The individual concentrations of four gases in a mixture are determined by: passing the mixture through a flowmeter (65), capillary (71), orifice (72) or sonic oscillator (76); transducing temperature (69), pressure (73, 74) and acoustic frequency measurements taken from the sensors; determining density (72), viscosity (71) and specific heat (76) of the mixture; forming three equations which respectively relate these three properties to individual gas concentrations; then solving the three equations under a condition requiring the sum of the concentrations to equal unity for the four unknown individual gas concentrations. A single oscillator can serve as both a sensor (flowmeter, acoustic velocimeter) and orifice. |