INFLOW EARTH AND SAND DETECTOR

PROBLEM TO BE SOLVED: To provide a detector capable of automatically detecting whether earth and sand flowing in a driving channel of a hydraulic power station exist or not, earth and sand flowing frequencies, inflow, etc. SOLUTION: In an inflow earth and sand detector, vibration acceleration in the case flowing earth and sand run against a screen detection bar is detected by an accelerometer 21, the full-wave rectification of the detected waveform is made by a full-wave rectifying circuit 25 and is integrated with an integrating circuit 27, at the same time, peak value is held with an amplitude maximum voltage hold circuit 28, and when an AD conversion starting time reaches in accordance with counting output of a timer 31, inflow of earth and sand is integrated with a counter 44 and, at the same time, integrating waveform and peak holding value are converted into digital signals with AD converters 41 and 42. Then, a data collection system 40 detects whether flowing earth and sand exist or not, earth and sand flowing frequencies, inflow, etc., based on the information, and a safety and maintenance equipment is automatically operated, if necessary.