Method and apparatus for testing hermetic seal integrity of sealed packages and containers

Apparatus for testing a package or container for hermetic seal integrity, which comprises:

• a test chamber into which a sealed test package having at least one semi-flexible surface, may be received;
• means for changing the pressure in said test chamber, from a first value to a second value, during the interval of a test cycle;
• means for measuring the pressure therein during said interval, and producing a first analog data signal proportional thereto;
• means within said test chamber for measuring the displacement of said semi-flexible surface during said interval, and producing a second analog data signal proportional thereto;
• means for sampling each of said first and second analog data signals during said interval of said test cycle, to produce a first discrete data sequence and said second discrete data sequence, so as to provide a measure of hermetic seal integrity of said sealed test package.

Apparatus for testing a package or container for hermetic seal integrity, which comprises:

• a test chamber into which a sealed test package having at least one semi-flexible surface, may be received;
• means for changing the pressure in said test chamber, from a first value to a second value, during the interval of a test cycle;
• means for measuring the pressure therein during said interval, and producing a first analog data signal proportional thereto;
• means within said test chamber for measuring the displacement of said semi-flexible surface during said interval, and producing a second analog data signal thereto;
• means for sampling each of said first and second analog data signals during said interval, to produce a first discrete data sequence and a second discrete data sequence therefrom respectively;
• means for computing at least one regression function from said first discrete data sequence and said second discrete data sequence, in accordance with the principles of linear regression analysis;
• and
• means for plotting and visually displaying said regression function against said first and second discrete data sequences, as to provide a visual indication of the statistical dependency of said second discrete data sequence on said first discrete data sequence, and at what values of test chamber pressure venting of said test package occurs.

A method of testing physical properties of a mechanical system characterizable by at least a first variable and a second variable, at least one of which is a random variable, which comprises the sequence of steps:

• observing, during the time interval of a test cycle, a system characterizable by at least a first variable and a second variable, at least one of which is a random variable;
• measuring, during said time interval of said test cycle, both said first variable and said second variable of said mechanical system, and
• producing during said time interval of said test cycle, a first analog data signal proportional to instantaneous value of said first variable and a second analog data signal proportional to instantaneous value of said second variable, wherein said first analog data signal is converted to a first discrete data sequence porportional to said instantaneous value of said first variable, and wherein said second analog data signal is converted to a second discrete data sequence proportional to said instantaneous value of said second variable;
• and
• computing a correlation estimate from said first discrete data sequence and said second discrete data sequence, so as to provide a measure of physical properties of said mechanical system.

Apparatus for testing physical properties of a mechanical system characterizable by at least a first variable and a second variable, at least one of which is a random variable, which comprises:

• means for rendering observable during the time interval of a test cycle, a mechanical system characterizable by at least a first variable and a second variable, where at least one of which is a random variable;
• means for measuring said first variable, during said time interval of said test cycle, and producing a first analog data signal proportional thereto;
• means for measuring said second variable, during said time interval of said test cycle, and producing a second analog data signal proportional thereto;
• means for sampling each of the said first and second analog data signals during said interval of said test cycle, to produce a first discrete data sequence and a second discrete data sequence, respectively;
• and
• means for computing a correlation estimate from said first discrete data sequence and said second discrete data sequence, so as to provide a measure of physical properties of said mechanical system.

Apparatus for testing physical properties of a mechanical system characterizable by at least a first variable and a second variable, at least one of which is a random variable, which comprises:

• means for rendering observable during the time interval of a test cycle, a mechanical system characterizable by at least a first variable and a second variable, where at least one of which is a random variable;
• means for measuring said first variable, during said time interval of said test cycle, and producing a first data signal proportional thereto;
• means for measuring said second variable, during said time interval of said test cycle, and producing a second data signal proportional thereto;
• means for sampling each of said first and second data signals during said interval, to produce a first discrete data sequence and a second discrete data sequence therefrom respectively;
• means for computing at least one regression function from said first discrete data sequence and said second discrete data sequence, in accordance with the principles of regression analysis;
• and
• means for plotting and visually displaying said regression function against said first and second discrete data sequences, as to provide a visual indication of the statistical dependency of said second discrete data sequence on said first discrete data sequence, and at what values of test chamber pressure venting of said test package occurs.

A method of testing a package or container for hermetic seal integrity, which comprises the sequence of steps:

• placing within a test chamber, a sealed test package with at least one semi-flexible surface;
• gradually changing the pressure within said test chamber from a first value to a second value, over the time interval of a test cycle,
• measuring, during said time interval of said test cycle, both the pressure within said test chamber and the displacement of said semi-flexible surface of said sealed test package, and
• producing during said time interval of said test cycle, a first analog data signal proportional to the pressure within said test chamber, and a second analog data signal proportional to the displacement of said semi-flexible surface of said sealed test package;
• converting said first analog data signal into a first discrete data sequence proportional to the pressure within said test chamber, and
• converting said second analog data signal into a second discrete data sequence proportional to the displacement of said semi-flexible surface of said sealed test package;
• and
• performing a segmental-type regression analysis of said second discrete data sequence on said first discrete data sequence including,
• segmenting said first discrete data sequence into a first plurality of subsequences and
• segmenting second discrete data sequence into a second plurality of subsequences, each said subsequence of said first plurality thereof corresponding to a subsequence of said second plurality thereof and being of equal length,
• computing at least one regression coefficient of a linear regression function for each corresponding first and second subsequences, and
• comparing said regression coefficients of adjacent linear regression functions for said corresponding first and second subsequences, as to determine at what values of vacuum pressure, the dependence of package displacement on vacuum pressure decreases, and thereby provide therefrom a measure of hermetic seal integrity of said test package.