| 摘要 |
PURPOSE:To set the optimum sensitivity of the AE sensor, by calculating the sensitivity value of the AE sensor based on the means of drive levels of a pseudo breakage signal generator and sensitivities of an AE sensor with respect to a large tool. CONSTITUTION:The sensitivity of an AE sensor 6 is adjusted with a pseudo breakage signal generator 4 driven according to the level corresponding to a tool used while the totals of the drive levels of the pseudo breakage signal generator 4 and the sensitivities of the AE sensor 6 are memorized into memories 10 and 11 in view of the fact that the totals are almost constant regardless of the size of the tool during the adjustment of sensitivity. Then, for a large tool in which the pseudo breakage signal level is too high to drive the pseudo breakage sinal generator 4 directly, the sensitivity value of the AE sensor 6 is calculated to be set as optimum sensitivity based on the mean of the drive levels and the sensitivities. |
