To judge the existence of a vacuum leak by a method wherein sound waves are impinged from one face of a sheetlike vacuum packaged product, the intensity of the sound waves which are transmitted up to a face on the opposite side is measured and the intensity of the transmitted sound waves is lowered in the case of the vacuum leak more than that in a case in which the vacuum leak is not generated.
A sound-wave generation device 2 is installed so as to be close to one face of a sheetlike vacuum packaged product 1, and a microphone 3 is installed so as to be close to a face on the side opposite to it. An oscillator which generates an electric signal to be sent to the sound-wave generation device 2 and a measuring device which analyzes a signal detected by the microphone 3 are built in a control device 4. In this manner, the sound waves are impinged from one face of the sheetlike vacuum packaged product 4, the intensity of the sound waves transmitted up to the face on the opposite side is measured, and a purpose can be achieved. The impinging method of the sound waves and the measuring method of the transmitted sound waves are not limited especially. Thereby, the sheetlike vacuum packaged product can be inspected by a simple installation, at low costs and quickly.
| JP2024511002 | Pressure gauge for inflatable articles |
YAMADA TAKASHI
SARUWATARI HIROYUKI
