Choked Flow Isolator for Noise Reduction in Analytical Systems
AssigneeAgilent Technologies, Inc.
InventorPhillip W. Barth
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Abstract
An apparatus and a method of making a measurement using the same. The apparatus includes a channel through which a fluid flows, a detector, and a choked flow channel. The detector measures a property of the fluid by generating a signal that depends on that property. The signal generated also depends on a pressure of the fluid in the detector. The choked flow channel receives the fluid at a first pressure after the fluid has been measured by the detector, and then transmits the fluid to a downstream location at a second pressure. The fluid reaches a supersonic velocity at one point in the choked flow channel. The choked flow channel may include a convergent-divergent nozzle or an orifice in a structure located in the choked flow channel.
Claims20
An apparatus comprising
- a channel through which a fluid flows;
- a detector for measuring a property of said fluid, said detector generating a signal that depends on said property and on a pressure of said fluid in said detector;
- and
- a choked flow channel that receives said fluid at a first pressure after said fluid has been measured by said detector, said choked flow channel transmitting said fluid to a downstream location at a second pressure, said fluid reaching a supersonic velocity at one point in said choked flow channel.
A method for making a measurement, said method comprising:
- causing a fluid having a property that is to be measured to flow through a detector that generates a signal that depends on said property and on a pressure of said fluid in said detector;
- and
- causing said fluid to reach a supersonic velocity after leaving said detector and prior to said fluid arriving at a location at a second pressure that is subject to pressure variations.
A gas chromatograph comprising:
- a carrier gas source that provides a carrier gas to a separation channel;
- a sample injection port that injects a sample to be analyzed into said carrier gas prior to said carrier gas entering said separation channel;
- a detector that measures a property of gas leaving said separation channel;
- and
- a choked flow channel that receives gas leaving said detector at a first pressure and discharges said gas at a second pressure, said gas reaching a supersonic velocity at a point in said choked flow channel.
Dependencies are inferred from the claim text.