| 摘要 |
<p>An instrument for detecting and reporting the location of a leak in thin-walled hermetically sealed packaging as between a seal leak and a sidewall leak. The instrument includes a needle, a vacuum pump, a means for creating at least two different steady-state ?P values across the packaging, a mass flow rate sensor, at least one pressure sensor, a device for generating a perceptible signal, and a processor. The instrument is operative for sensing the external pressure outside the packaging's retention chamber, sensing the internal pressure within the packaging's retention chamber and transmitting an internal pressure signal, sensing the mass flow rate of gas pulled from the packaging's retention chamber, calculating a first ratio of mass flow rate to ?P at a first ?P and a second ratio of mass flow rate to ?P at a second ?P, calculating a variation between the first ratio and the second ratio, and generating a first perceptible signal indicating that the packaging contains a sidewall leak when the variation is equal to or greater than a threshold value and generate a second perceptible signal indicating that the packaging contains a seal leak when the variation is less than the threshold value.</p> |
