中文摘要：

运用实验的方法得出了差分振子检测的上下限频率，振子检测的上限频率只要满足采样定理即可．振子NT限检测频率与采样频率有关，在采样频率一定的条件下，振子的下限检测频率大约为采样频率的1／650，当采样频率过高时，不论振子相图收敛于极点还是极环都呈现出饼形．利用差分振子相图变化的特点，对现场数据进行分析，发现了设备故障从无到有的相图变化，为设备状态检测提供了一种方法．

英文摘要：

The upper and lower limits of detected frequency for differential resonator were obtained by experimental method. The detected upper limit frequency only need to satisfy the sampling theorem while the detected lower one is related to sampling frequency. Under the condition of certain sampling frequency, the lower detecting frequency of differential resonator was about 1/650 of sampling frequency. When the sampling frequency was too high, whether converging to the pole or the polar ring, the phase diagram of differential resonator would present as a pie. Applying this method to the high speed rolling mill fault diagnosis, the phase diagram of the vibration signals changed from pole to polar ring, which implied the running state from normal to incipient fault, thereby providing an effective technology for condition monitoring and fault diagnosis of mechanical equipment.