초록 ▼

To measure the leakage rate in hollow bodies, the throughflow rate of the air flowing into the leaky hollow body is automatically measured and indicated numerically at a given test pressure. This is achieved by feeding fluid from a prechamber filled with fluid under measuring pressure to two measuri

To measure the leakage rate in hollow bodies, the throughflow rate of the air flowing into the leaky hollow body is automatically measured and indicated numerically at a given test pressure. This is achieved by feeding fluid from a prechamber filled with fluid under measuring pressure to two measuring chambers (4,5) equipped with a testpiece and reference housing and having an identical cavity. The pressure decrease in a prechamber (1) is thereupon evaluated as a measure of the accessible volume in the two measuring chambers (4,5) and is compared with the volume given as permissible. If the measured accessible volume is higher than the volume given by the size of the chamber, the testpiece is qualified as highly leaky. If the volumes in the two chambers (4,5) correspond to one another, the chambers (4,5) are separated from the prechamber and the pressure difference between the chambers (4,5) and its trend in time are detected, in order to determine from this a measure of the tightness of the testpiece. The tightness of hollow bodies can thereby be detected quickly and accurately.

대표청구항 ▼

A method for testing the fluid-tightness of hollow bodies by exposing a hollow body to be tested as a testpiece and a reference hollow body to a test fluid, said method comprising: disposing said testpiece in a first measuring chamber and said reference hollow body in a second measuring chamber, sai

A method for testing the fluid-tightness of hollow bodies by exposing a hollow body to be tested as a testpiece and a reference hollow body to a test fluid, said method comprising: disposing said testpiece in a first measuring chamber and said reference hollow body in a second measuring chamber, said first and second measuring chambers having identical volumes; in a prechamber, creating an overpressure or an underpressure of test fluid relative to fluid pressures within said first and second measuring chambers; subsequently establishing fluid communication between said prechamber and said first and second measuring chambers; measuring a change in the overpressure or the underpressure of the test fluid in said prechamber as an indicator of a free volume of fluid admitted to or expelled from said first and second measuring chambers; if said free volume of fluid admitted to or expelled from said first and second measuring chambers exceeds a predetermined value, determining that said testpiece is leaky and discarding said testpiece; and if said free volume of fluid admitted to or expelled from said first and second measuring chambers substantially equals said predetermined value, a) terminating said fluid communication between said prechamber and said first and second measuring chambers, b) measuring, by means of a gauge disposed in fluid communication between said first and second measuring chambers, a pressure differential between said first and second measuring chambers and variation thereof with time, and c) determining the fluid-tightness of said testpiece based on said pressure differential and said variation thereof with time.