| 摘要 |
PURPOSE:To measure fine leakage easily and quantitatively by allowing an acoustic sensor to detect an acoustic signal generated when fine liquid or gas leaks from a valve in a closed state, and converting its detection signal into a leak flow rate and outputting it. CONSTITUTION:When a leak occurs to the valve 1, an acoustic signal corresponding to the leak is generated at the leak part. This is detected by the acoustic sensor 2 and amplified by a signal amplifier 3, and an incorporated filter removes frequency components except in the frequency band of the acoustic signal generated by the leak. Further, a background noise in the signal from the acoustic sensor 2 is removed to improve the S/N ratio. The signal after the noise removal is inputted to an RM meter 4 and converted into an RMS value. The output of the RMS meter 4 is inputted to an RMS value/leak flow rate converter 5 and converted into leakage. A signal indicating the leakage is sent to an output part 6 to perform display and recording and generate an alarm when the leakage exceeds a set value. Consequently, fine leakage is measured easily, quantitatively, and automatically. |
