| 摘要 |
PROBLEM TO BE SOLVED: To provide an air leak measuring device suitable for inspecting simply and accurately airtightness of a packaging medium for packaging an article airtightly. SOLUTION: This device is equipped with a hollow needle piercing the packaging medium for packaging the article airtightly, a vacuum tank having a prescribed tank capacity and depressurized up to a prescribed pressure, a valve mechanism for communicating the vacuum tank with the hollow needle and sucking the inside of the packaging medium, a pressure sensor for detecting the pressure inside the vacuum tank, and a measuring means for determining the air leak quantity of the packaging medium from a pressure change per prescribed time detected through the pressure sensor. On condition that the velocity of the air leaking from the packaging medium becomes constant (a sound velocity) in a prescribed pressure range, the air leak quantity of the packaging medium is calculated from the expression, [the air leak quantity]=[pressure difference]×[tank capacity]/([inflow time]×[atmospheric pressure]). COPYRIGHT: (C)2004,JPO
|
