Systems and methods for liquid dynamic pressure testing

Patent metadata

Field	Value
Publication number	US-9897506-B2
Application number	US-201514801002-A
Country	US
Kind code	B2
Filing date	Jul 16, 2015
Priority date	Jul 16, 2015
Publication date	Feb 20, 2018
Grant date	Feb 20, 2018

Abstract

Certain implementations of the disclosed technology may include systems and methods for dynamic pressure testing of transducers in communication with a liquid. A method is provided that can include dynamically pressurizing a liquid in a cavity associated with a housing. While dynamically pressurizing the liquid, the method includes simultaneously measuring: a change in volume of the liquid; a test frequency response, by a test transducer in communication with the liquid; and a reference frequency response, by a reference transducer in communication with the liquid. The method may further determine a normalized frequency response of the test transducer, based at least in part on the test frequency response and the reference frequency response. The method may further provide an indication of the normalized frequency response of the test transducer and an indication of the bulk modulus of the liquid.

First claim

The invention claimed is:

1. A computer-implemented method, comprising:
dynamically pressurizing a liquid in a cavity associated with a housing;
while dynamically pressurizing the liquid, simultaneously measuring:
a change in volume of the liquid;
a test frequency response, by a test transducer in communication with the liquid;
a reference frequency response, by a reference transducer in communication with the liquid;

determining, by one or more computer processors, a normalized frequency response of the test transducer, based at least in part on the test frequency response and the reference frequency response; and
outputting an indication of the normalized frequency response of the test transducer.

2. The method of claim 1 , wherein the simultaneously measuring further comprises: measuring, by one or more of the reference transducer and the test transducer, a pressure of the liquid in the housing;
measuring a displacement of a piston structure in communication with the liquid;
determining a change in volume of the liquid based on the displacement of the piston;
determining a bulk modulus of the liquid based on the measured pressure and the determined change in volume of the liquid; and
outputting an indication of the bulk modulus of the liquid.

3. The method of claim 1 , wherein the simultaneously measuring further comprises: measuring a speed of sound in the pressurized liquid, and
computing a bulk modulus of the liquid based on the measured speed of sound in the pressurized liquid.

4. The method of claim 1 , further comprising filtering, by a mechanical filter, the pressurized liquid in communication with the test transducer.

5. The method of claim 4 , wherein the mechanical filter comprises one or more of:
a porous structure;
a narrow tube;
a cavity;
and
a diameter of a test diaphragm associated with the test transducer that differs from a diameter of a reference diaphragm associated with the reference transducer.

6. The method of claim 1 , wherein the determining the normalized frequency response comprises:
storing in a memory in communication with the one or more computer processors, the test frequency response and the reference frequency response; and
dividing, by the one or more computer processors, the test frequency response by the reference frequency response.

7. The method of claim 1 , wherein the test and reference transducers comprise different structures.

8. The method of claim 1 , wherein the test and reference transducers comprise substantially similar structures.

9. The method of claim 1 , wherein the test transducer and the reference transducers are disposed at an equal vertical position in the housing.

10. A test apparatus, comprising:
a housing comprising a cavity configured for containing a liquid;
a reference transducer mounted on the housing and configured for communication with the liquid;
a test article comprising a test transducer and a filter, the test article coupled to the housing and further configured for communication with the liquid;
at least one acquisition system in communication with the reference transducer and the test transducer;
a piston in communication with the liquid and configured to slidingly engage with a portion of the cavity;
wherein the acquisition system is configured for simultaneously:
determining a bulk modulus of the liquid; and
determining a normalized frequency response of the test article.

11. The test apparatus of claim 10 , wherein determining the normalized frequency response comprises:
storing, in a memory in communication with the acquisition system:
a test frequency response of the test transducer; and
a reference frequency response of the reference transducer; and

dividing, by the acquisition systems, the test frequency response by the reference frequency response.

12. The test apparatus of claim 10 , wherein determining the bulk modulus comprises:
dynamically pressurizing, by the piston, the liquid in the cavity;
measuring, by one or more of the reference transducer and the test transducer, a pressure of the liquid;
measuring a displacement of the piston in communication with the liquid;
determining a change in volume of the liquid based on the displacement of the piston; and
determining the bulk modulus of the liquid based on the measured pressure and the determined change in volume of the liquid.

13. The test apparatus of claim 10 , further comprising:
a first transducer disposed at a first distance from the piston and configured to provide a first measurement signal; and
a second transducer disposed at a second distance from the piston and configured to provide a second measurement signal;
wherein determining the bulk modulus comprises measuring a speed of sound in the liquid, wherein a speed of sound in the liquid is based on a time difference of the first and second measurement signals.

14. The test apparatus of claim 10 , wherein the filter comprises one or more of:
a porous structure;
a narrow tube;
a cavity;
and
a diameter of the test diaphragm associated with the test article that differs from a diameter of a reference diaphragm associated with the reference transducer.

15. The test apparatus of claim 10 , wherein the acquisition system is configured to compute a normalized frequency response of the test article based on dividing a test frequency response of the test transducer by a reference frequency response of the test article.

16. The test apparatus of claim 10 , wherein the test and reference transducers comprise different structures.

17. The test apparatus of claim 10 , wherein the test and reference transducers comprise substantially similar structures.

18. The test apparatus of claim 10 , wherein the test article and the reference transducer are disposed at an equal vertical position in the housing.

19. The test apparatus of claim 10 , wherein the test article and the reference transducer are equidistant from the piston.

Assignees

• Kulite Semiconductor Products Inc

Inventors

• Hurst Adam

Classifications

• G01L27/005 Primary

  Apparatus for calibrating pressure sensors · CPC title

• G01L27/007

  Malfunction diagnosis, i.e. diagnosing a sensor defect · CPC title