Patent ID: 8042378

Claim:
A gas amount measuring device for measuring an amount of gas contained in molten metal or an amount of gas attached to an inclusion, comprising: a vacuum container containing therein the molten metal; a first pipe connected to the vacuum container, an air release valve being attached to the first pipe; a second pipe connected to the vacuum container, a calibration gas generator being attached to the first pipe; a third pipe connected to the vacuum container, a vacuum gauge, a first valve, a leak valve, a second valve, a turbomolecular pump, a third valve, and a roughing pump being attached to the third pipe in order from a vacuum container side; a first bypass pipe connecting the third pipe between the vacuum container and the first valve to the third pipe between the leak valve and the second valve, a fourth valve being attached to the first bypass pipe; and a second bypass pipe connecting the third pipe between the leak valve and the second valve to the third pipe between the third valve and the roughing pump, a fifth valve being attached to the second bypass pipe.