Apparatus and method for eliminating varying pressure fluctuations in a pressure transducer

Patent metadata

Field	Value
Publication number	US-9709450-B2
Application number	US-201314057745-A
Country	US
Kind code	B2
Filing date	Oct 18, 2013
Priority date	May 9, 2008
Publication date	Jul 18, 2017
Grant date	Jul 18, 2017

Abstract

A differential pressure transducer employing a coiled tube to eliminate varying pressure fluctuations is provided. In one embodiment, a method comprises receiving, at an inlet tube of a dampening chamber, a main pressure, wherein the main pressure includes a static pressure component and a dynamic pressure component; filtering, by the inlet tube, at least a portion of the dynamic pressure component of the main pressure; outputting, from the inlet tube, a first filtered main pressure; receiving, at a volume cavity of the dampening chamber, the first filtered main pressure, wherein the volume cavity is operatively coupled to the inlet tube; filtering, by the volume cavity, at least a portion of the dynamic pressure component of the first filtered main pressure; outputting, from the volume cavity, a second filtered main pressure; and wherein the dampening chamber is tuned to a predetermined resonance frequency.

First claim

The invention claimed is:

1. A method, comprising:
tuning an adjustable dampening chamber for a predetermined resonance frequency, wherein the adjustable dampening chamber comprises a machined plate inlet tube, a machine plate inlet tube cover having an inlet hole, and an adjustable volume cavity in communication with the inlet tube, wherein the tuning comprises:
selectively controlling a length of the inlet tube by alignment of the inlet hole of the machine plate inlet tube cover with respect to the machined plate inlet tube;
controlling a cross-sectional diameter of the inlet tube; and
controlling a volume of the adjustable volume cavity;

installing, in a housing of a differential pressure sensor, the adjustable dampening chamber, wherein the differential pressure sensor comprises a diaphragm, and wherein the housing defines a main pressure port and a reference pressure port;
configuring the main pressure port to be in communication with a first surface of the diaphragm;
configuring the reference pressure port to be in communication with the inlet tube, wherein the reference pressure port is adapted to receive a reference pressure having a static pressure component and a dynamic pressure component, and wherein the inlet tube is configured to filter at least a portion of the dynamic pressure component of the reference pressure and to output to the adjustable volume cavity, a first filtered reference pressure;
wherein the adjustable volume cavity is tuned to reduce at least a portion of the dynamic pressure component of the first filtered reference pressure and to output to a second surface of the diaphragm, a second filtered reference pressure.

2. The method of claim 1 , further comprising:
coupling a transducer to the diaphragm for measuring a difference between the main pressure and the second filtered reference pressure.

3. The method of claim 1 , wherein the inlet tube is machined in a spiral shape.

4. The method of claim 1 , wherein tuning the adjustable dampening chamber further comprises:
machining a shape on a surface of the adjustable dampening chamber; and
securing a cover over the machined shape to form at least a portion of the inlet tube.

5. The method of claim 1 , wherein the adjustable dampening chamber comprises one piece, and wherein the adjustable volume cavity and the inlet tube are integrated in the adjustable dampening chamber.

6. The method of claim 1 , wherein the adjustable dampening chamber is tuned to the predetermined resonance frequency using a Helmholtz equation.

7. The method of claim 1 , wherein the inlet tube is defined by a cross-sectional diameter ranging from about five thousandth of an inch (5 mils) to about fifty thousandth of an inch (50 mils).

8. The method of claim 1 , wherein the inlet tube has a length of about twenty-five hundredths (0.25) of an inch to about five (5) inches.

9. The method of claim 1 , wherein a cross-section of the inlet tube is circular.

10. The method of claim 1 , wherein the dynamic pressure component includes frequencies greater than one hundred Hertz (100 Hz).

11. The method of claim 1 , wherein the volume cavity includes an array of volume cavities.

Assignees

• Kulite Semiconductor Products Inc

Inventors

• Kurtz Anthony D
• Kane Adam
• Martin Richard
• Gardner Robert

Classifications

• G01L7/022 Primary

  constructional details, e.g. mounting of elastically-deformable gauges (G01L7/041, G01L7/061, G01L7/082, G01L7/102, G01L7/163, G01L7/182 take precedence) · CPC title

• G01L9/06

  of piezo-resistive devices · CPC title

• G01L19/02

  Arrangements for preventing, or for compensating for, effects of inclination or acceleration of the measuring device; Zero-setting means (for aneroid barometers G01L7/14) · CPC title

• G01L13/025

  using diaphragms · CPC title

• G01L19/0609 Primary

  Pressure pulsation damping arrangements · CPC title