Method and apparatus for real time gas analysis

A modular apparatus for analyzing a fluid, comprising:

• a disposable fluidic sensor module comprising:
• a plate-like member having an inlet adapted to receive a flow of the fluid and an outlet for exhausting the flow of the fluid;
• a fluidic flowmeter formed in said plate-like member in a path between the inlet and the outlet, said fluidic flowmeter being responsive to the flow of the fluid to generate an output indicative of a flow rate of the fluid, and a capillary structure formed in said plate-like member in a path between the inlet and the outlet said capillary structure restricting a flow of the fluid such that a pressure drop across said capillary structure is related to a viscosity of the fluid;
• a replaceable transducer module connectable to said fluidic sensor module via a separable interface, said replaceable transducer module comprising transducers for measuring physical conditions of the fluid flowing through said fluidic sensor module;
• an expendable electronics package connectable to said replaceable transducer module, said expendable electronics comprising a processor responsive to transducer signals generated by said transducers for determining properties of the fluid;
• and
• a sonic oscillator formed in said plate-like member in a path between the inlet and the outlet, said sonic oscillator generating flow oscillations having a frequency related to the specific heat of the fluid.

A disposable fluidic sensor module for an apparatus for analyzing a fluid, the disposable fluidic sensor comprising:

• a plate-like member having an inlet adapted to receive a flow of the fluid and an outlet for exhausting the flow of the fluid;
• a fluidic oscillator formed in said plate-like member in a path between the inlet and the outlet and having a period of oscillation substantially proportional to a transit time of the fluid from an input of the fluidic oscillator to an output of the fluidic oscillator, wherein the period of oscillation of the fluidic oscillator is substantially independent of the density and viscosity of the fluid, said fluidic oscillator being responsive to the flow of the fluid to generate an output indicative of a flow rate of the fluid;
• and
• a capillary structure formed in said plate-like member in a path between the inlet and the outlet, said capillary structure restricting a flow of the fluid such that a pressure drop across said capillary structure is related to a viscosity of the fluid.

A modular apparatus for analyzing a fluid, comprising:

• a disposable fluidic sensor module comprising:
• a plate-like member having an inlet adapted to receive a flow of the fluid and an outlet for exhausting the flow of the fluid;
• a fluidic oscillator formed in said plate-like member in a path between the inlet and the outlet and having a period of oscillation substantially proportional to a transit time of the fluid from an input of the fluidic oscillator to an output of the fluidic oscillator, wherein the period of oscillation of the fluidic oscillator is substantially independent of the density and viscosity of the fluid, said fluidic flowmeter being responsive to the flow of the fluid to generate an output indicative of a flow rate of the fluid;
• and a capillary structure formed in said plate-like member in a path between the inlet and the outlet, said capillary structure restricting a flow of the fluid such that a pressure drop across said capillary structure is related to a viscosity of the fluid;
• a replaceable transducer module connectable to said fluidic sensor module via a separable interface, said replaceable transducer module comprising transducers for measuring physical conditions of the fluid flowing through said fluidic sensor module;
• and
• an expendable electronics package connectable to said replaceable transducer module, said expendable electronics comprising a processor responsive to transducer signals generated by said transducers for determining properties of the fluid.

A disposable fluidic module for sensing plural characteristics of a flowing medium, said module comprising:

• an inlet port for receiving the flowing medium at said module;
• a flowmeter for receiving the flowing medium from said inlet port and configured in the form of a fluidic oscillator for transversely oscillating said flowing medium at an oscillation frequency that varies as a function of the velocity of said flowing medium, said fluidic oscillator being defined as a plurality of flow channels;
• and
• a capillary member for receiving output flow from said fluidic oscillator and establishing a pressure drop in said output flow, said capillary member comprising a common flow entrance, a common flow exit and a plurality of capillary passages extending in flow communication between said entrance and exit, said capillary passages having transverse cross-sections that are very much smaller than transverse cross-sections of said flow channels in said fluidic oscillator;
• wherein said module is a rigid member, and wherein said fluidic oscillator and said capillary passages are formed as flow passages defined in said rigid member.