Method and apparatus for detecting leaks

• US 6,860,141 B2
• Filed: 06/15/2004
• Issued: 03/01/2005
• Est. Priority Date: 03/06/2003
• Status: Expired due to Fees

• Current Assignee: Cincinnati Test Systems, Inc. (TASI Holdings, Inc.)
• Original Assignee: Cincinnati Test Systems, Inc. (TASI Holdings, Inc.)
• Inventors: Borntrager, Ryan R., McCoy, Fred Grant, Fazekas, Jonathan Mark
• Primary Examiner(s): CYGAN, MICHAEL T
• Application Number:
  US10/868,158
• Publication Number:
  US 20040226345A1
• Time in Patent Office: 259 Days
• Field of Search: 73/407, 702/51, 340/605
• US Class Current: 73/40.7
• CPC Class Codes: G01M 3/225 for welds
• CPC Class Codes: G01M 3/229 removably mounted in a test cell
• CPC Class Codes: G01N 1/26 with provision for intake from several spaces
• CPC Class Codes: G01N 7/10 by allowing diffusion of components through a porous wall and measuring a pressure or volume difference

Abstract

The present invention relates to a sensor apparatus configured to detect the presence of a gas, such as a tracer gas and a leak detection apparatus configured to detect the presence of a tracer gas and indicate the location of a leak. The leak detection apparatus may further be configured to quantify the leak rate at the leak location.

Claims

1. A method for sequentially testing multiple instances of a part under test to determine if a first region of the part under test contains a leak, the method comprising the steps of:

positioning a first instance of the part under test in a test region;

introducing a tracer gas such that a first side of the first region of the first instance of the part under test is at a higher pressure than a second side of the first region of the first instance of the part under test;

positioning a plurality of sensors proximate to the second side of the first region of the first instance of the part under test, each of the plurality of sensors configured to detect the presence of a tracer gas emanating from the leak and to provide a sensing signal;

monitoring each of the plurality of sensors for a first period of time to determine if the tracer gas is being detected by any of the plurality of sensors;

providing a leak detection signal in response to at least a first sensor of the plurality of sensors detecting the presence of the tracer gas, the leak detection signal including leak location information representative of the location of the leak in the first region based on the sensing signals received from at least the first sensor and a second sensor of the plurality of sensors;

evacuating the tracer gas from the first side of the first region of the first instance of the part under test;

removing the first instance of the part under test from the test region; and

positioning a second instance of the part under test in the test region.

2. The method of claim 1, further comprising the steps of:

introducing a tracer gas such that a first side of the first region of the second instance of the part under test is at a higher pressure than a second side of the first region of the second instance of the part under test;

positioning a plurality of sensors proximate to the second side of the first region of the second instance of the part under test, each of the plurality of sensors configured to detect the presence of a tracer gas emanating from the leak and to provide a sensing signal;

monitoring each of the plurality of sensors for a first period of time to determine if the tracer gas is being detected by any of the plurality of sensors;

providing a leak detection signal in response to at least a first sensor of the plurality of sensors detecting the presence of the tracer gas, the leak detection signal including leak location information representative of the location of the leak in the first region based on the sensing signals received from at least the first sensor and a second sensor of the plurality of sensors;

evacuating the tracer gas from the first side of the first region of the second instance of the part under test;

removing the second instance of the part under test from the test region.

3. The method of claim 1, further comprising the step of providing a first indication of the location of the leak of the first instance of the part under test.

4. The method of claim 3, wherein the first indication includes displaying on a display a first representation of the first instance of the part under test and a sensor icon positioned on the first representation, the sensor icon corresponding to a location of the sensor which is proximate to the location of the leak.

5. The method of claim 3, wherein the first indication includes displaying on a display a first representation of the first instance of the part under test and a leak graphic positioned on the first representation, the position of the leak graphic corresponding to the location of the leak.

6. The method of claim 3, further comprising the step of providing a leak rate signal in response to the at least first sensor of the plurality of sensors detecting the presence of the tracer gas, the leak rate signal including leak rate information representative of the leak rate of the leak.

7. The method of claim 1, wherein the step of providing the leak detection signal includes comparing the sensing signal of the first sensor and the sensing signal of the second sensor, the location of the leak being determined at least in part based on the comparison of the sensing signal of the first sensor and the sensing signal of the second sensor.

8. The method of claim 7, wherein the comparison of the sensing signal of the first sensor and the sensing signal of the second sensor is performed by a controller.

9. The method of claim 8, further comprising the step of providing a first indication of the location of the leak of the first instance of the part under test, the first indication including displaying on a display a first representation of a part under test and a sensor icon positioned on the first representation, the sensor icon corresponding to a location of the sensor which is proximate to the location of the leak.

10. The method of claim 8, further comprising the step of providing a first indication of the location of the leak of the first instance of the part under test, the first indication including displaying on a display a first representation of a part under test and a leak graphic positioned on the first representation, the position of the leak graphic corresponding to the location of the leak.

11. The method of claim 1, wherein the step of positioning the plurality of sensors comprises the steps of coupling at least a portion of the plurality of sensors to a first fixture, the first fixture being moveable between a first position wherein the portion of the plurality of sensors is spaced apart from the first region and a second position wherein the portion of the plurality of sensors are positioned adjacent the first region.

12. The method of claim 11, wherein the first fixture is configured to substantially enclose the first region such that tracer gas emanating from the leak is substantially retained by the first fixture.

13. The method of claim 11, wherein the first fixture and the part under test cooperate to provide a non-evacuated space.

14. The method of claim 1, further comprising the step of providing a leak rate signal in response to the at least first sensor of the plurality of sensors detecting the presence of the tracer gas, the leak rate signal including leak rate information representative of the leak rate of the leak.

15. The method of claim 14, wherein the step of providing the leak rate signal comprises the steps of:

determining average concentration of tracer gas detected by the plurality of sensors;

monitoring the change in average concentration of tracer gas detected by the plurality of sensors over a first time period;

determining the rate of change of the average concentration over time; and

comparing the rate of change of average concentration to known leak rates.

16. The method of claim 1, further comprising the step of sending the leak detection signal across a network to a remote device.

17. The method of claim 1, further comprising the step of determining if a correlation exists between the location of a leak in a first part under test and the location of a leak in a second part under test.

18. The method of claim 17, further comprising the step of sending the leak detection signal across a network to a remote device.