Patent ID: 8379209

Claim:
A non-destructive inspection device for an oxygen concentration in a bag-shaped container, the non-destructive inspection device being provided in a liquid filler for feeding a liquid into the bag-shaped containers held by container holders on a transport unit and transported along a transport path including at least a liquid filling area, a sealing area, and an inspection area, the non-destructive inspection device emitting, in the inspection area of the transport path, a laser beam to a gas phase portion of the bag-shaped container filled with the liquid and measuring an oxygen concentration in the bag-shaped container based on an amount of transmitted light, the non-destructive inspection device comprising: a pair of right and left moving members provided on right and left of the inspection area of the transport path such that the moving members are moved toward and away from the bag-shaped container by a moving device; a laser emitting section that is provided on one of the moving members and emits the laser beam for measuring the oxygen concentration; and a laser receiving section that is provided on the other moving member and receives the laser beam, wherein the non-destructive inspection device further comprises inert gas chambers respectively on end faces of the laser emitting section and the laser receiving section on the moving members, the inert gas chambers being made of a translucent material with a constant length in a depth direction, and in measurement of the oxygen concentration in the inspection area, the pair of right and left moving members are brought close to each other to contact the end faces of the laser emitting section and the laser receiving section with surfaces of the gas phase portion of the bag-shaped container, so that the gas phase portion has a constant thickness and air is removed between the end faces of the laser emitting section and the laser receiving section and the surfaces of the gas phase portion.