在相同观测条件下，选用平凉地震台北山2号泉水样作为实验目标，用FD-125型模拟水氡仪与SD-3B型数字水氡仪进行了对比观测实验，对两种仪器产出的数据对比分析；搜集全国用相同方法观测的5个台的观测资料进行对比分析，结果表明：FD-125型模拟水氡仪性能明显优于SD-3B型数字水氡仪。

In the same observation conditions, to Gansu Pingliang station FD-125 simulation of water radon and SD-3B type digital water radon was conducted over of comparative experiment research of two kinds of instruments, experimental data output indicators were compared and analyzed; in addition to collect the same method for observing the 5 station the observational data were compared and analyzed, research shows that: the FD-125 simulation of water radon instrument performance is superior to that of SD-3B type digital water radon meter.