METHOD FOR MEASURING VIBRATION INTENSITY

PROBLEM TO BE SOLVED: To measure the vibration intensity with a small memory capacity while keeping the speed and accuracy of operation by storing the speed response value every prescribed time interval, determining a maximum value among a prescribed number of values as a maximum speed response value, determining a seismic intensity value from the maximum speed response value, and repeating the operation. SOLUTION: An (n) times an operation interval Δt of a prescribed time interval from the past to the current time is referred to as a time window. A value only in the time window is stored in the memory area for speed response value v(t). Assuming that the current time is t5, the time window is from t2 to t5 and four speed response values v(t2) to v(t5) are stored in the memory area. When that time is a multiple of n, the time having largest absolute value is stored as the maximum speed response value Sv at the time t5 in another memory area. Similarly, the maximum speed response value Sv is selected for other natural period T. An SI value (seismic intensity) at the time t5 is then determined from all maximum speed response values Sv. On the contrary to be conventional method, the speed response value v(t) is not required to be determined based on an acceleration detection signal.