We find that the noise level of the record is very low . even in weak ground motion condition the digital broad - band record has high signal - to - noise ratio when the period is as long as 20 sec . the signal - to - noise ratio of the velocity - type records is lower than that of the acceleration - type records 木义发现，数宇宽频带记录的啪卢水平很低，在川朔k达205时，即仗在弱地震动的惰况下，还具有较高的信啪比，并且浊度型记录的信噪比禾厂加让度型门录的信噪比。
