| 摘要 |
PURPOSE:To detect a total quantity of a discharged gas through distinguishing of bubbles from dust, by installing a high-pass filter circuit which detects only a change in a light intensity due to bubbles from measurements of a change in an intensity of a projecting light due to bubbles produced as a result of the increase in an internal pressure of an object to be measured placed in a liquid tank. CONSTITUTION:An object to be measured immersed in a liquid container 1 is heated by a heater 3 to increase the internal pressure of the object 4 to be measured, and bubbles 5 produced because of leaking of gas are collected to a place by a collecting device 6. A light flux 8 from a light source 7 is reduced in light owing to bubbles and enters a collecting element 9. An output thereof is inputted to a signal processing device 11 via a high-pass filter circuit 10 to compute a quantity of bubbles produced, and a deciding device 12 decides whether the object 4 to be measured is good or bad. Suspension mixed in liquid 2 is moved to a low speed by a thermal convection, whereby a signal generated thereby is shut off by the high-pass filtering circuit 10 and only bubbles produced by discharge gas are detected. |
