Quick leak detection on dimensionally stable/slack packaging without the addition of test gas

Patent metadata

Field	Value
Publication number	US-10845266-B2
Application number	US-201916243513-A
Country	US
Kind code	B2
Filing date	Jan 9, 2019
Priority date	Nov 16, 2011
Publication date	Nov 24, 2020
Grant date	Nov 24, 2020

Abstract

A method for leak detection of a test specimen includes providing an evacuable film test chamber which is operatively coupled to a pressure measuring device, and at least one processor operatively coupled to the pressure measuring device; measuring a pressure within the evacuable film test chamber by the pressure measuring device at predetermined times during a measurement period of time; calculating by the processor, a first or higher order derivative of a pressure change with respect to time at a first predetermined time, and a first or higher order derivative of a pressure change with respect to time at least at a second predetermined time during the measurement period of time, to provide at least a pair of derivative values; and categorizing by the processor a leaky or tight state of the specimen under test by a pattern recognition process based on the pair of derivative values.

First claim

What is claimed is:

1. A method for leak detection of a test specimen comprising:
providing an evacuable film test chamber having at least one wall area of a flexible material, said evacuable film test chamber operatively coupled to a pressure measuring device, and at least one or more processors operatively coupled to said pressure measuring device, said at least one or more processors programmed to control components of said evacuable film test chamber and to perform a pattern recognition process, and a specimen disposed within said evacuable film test chamber;
evacuating said evacuable film test chamber;
measuring a pressure within said evacuable film test chamber by said pressure measuring device at predetermined times during a measurement period of time;
calculating by said at least one or more processors, a first or second order derivative of a pressure change at a first predetermined time, and a first or second order derivative of a pressure change at least at a second predetermined time during said measurement period of time, to provide at least a pair of derivative values; and
categorizing by said at least one or more processors a leak state of said specimen under test by said pattern recognition process based on said pair of derivative values, as either a tight specimen which is substantially not leaking, or as a leaky specimen which is leaking.

2. The method of claim 1 , wherein said step of calculating a derivative comprises a first derivative or slope at said first predetermined time and at said second predetermined time.

3. The method of claim 1 , wherein said step of calculating a derivative comprises a second or higher order derivative of pressure change with time at said first predetermined time and at said second predetermined time.

4. The method of claim 1 , wherein said step of measuring further comprises making a course leak detection measurement by measuring said pressure inside said evacuable film test chamber during a pump-off phase.

5. The method of claim 1 , wherein said step of providing comprises providing said evacuable film test chamber having a gas-binding absorber material disposed within a volume connected to said evacuable film test chamber.

6. The method of claim 5 , wherein said gas-binding absorber material comprises a zeolith.

7. The method of claim 5 , wherein said gas-binding absorber material is disposed within a connecting channel between said evacuable film test chamber and said pressure measuring device.

8. The method of claim 7 , further comprising a shut-off valve disposed in said connecting channel, said shut-off valve providing a selectable separation of said gas-binding absorber material from said volume of said evacuable film test chamber.

9. The method of claim 1 , wherein said pattern recognition process comprises a recognition of points within a leaky region or a tight region of a graph space.

10. The method of claim 1 , wherein said pattern recognition process comprises a linear discriminant analysis (LDA) process.

11. The method of claim 10 , wherein at least one discriminant function is defined by a series of characteristic variables measured during a training or teach in series of measurements.

12. The method of claim 11 , wherein said series of characteristic variables comprise a derivative of first or higher order of said pressure change with respect to time at said first and said second predetermined time.

Assignees

• Inficon Gmbh

Inventors

• Decker Silvio
• Wetzig Daniel
• Bruhns Hjalmar
• Mebus Stefan

Classifications

• G01M3/205

  Accessories or associated equipment; Pump constructions · CPC title

• G01M3/229

  removably mounted in a test cell · CPC title

• G01M3/3209 Primary

  Details, e.g. container closure devices · CPC title

• G01M3/3218 Primary

  for flexible or elastic containers · CPC title