对FEI公司TecnaiG-20型200kV透射电子显微镜,接连出现的三例高压故障现象、原因及维修处理方法进行了分析。结果表明:虽然都是高压故障,但产生的原因各不相同;故障一产生的原因是电缆头上原涂有的绝缘硅胶老化,使绝缘性能下降造成的,可通过重涂绝缘硅胶的方法排除;故障二产生的原因是加速极电阻损坏,造成电子枪内部放电,可通过更换损坏的放电柱和加速电阻的方法排除;而故障三是因电子枪内部的磁瓶损坏产生的,可通过对损坏磁瓶进行修复的方法排除。通过维修处理,三例高压故障都得到排除,取得了良好的效果。

Three cases of high-voltage fault phenomena, cause and repairing method for TecnaiG-20 type 200 kV transmission electron microscope manufactured by FEI were analyzed. The results illustrate that all these three faults came from electron gun, but the causes were different from each other. The first fault was due to the aging of insulating silica gel on surface of the cable head, which caused decline in insulating property and could be repaired by recoating new insulating silicagel method. The second fault was owing to the damage of accelerating pole resistance, which caused a discharge in internal of the electron gun. The fault could be repaired by replacingit with a new part. The third fault arose from the damage of magnetic bottle in internal of the electron gun, which could be repaired by treatment to the magnetic bottle. By analyzing and repairing, all the high-voltage faults were removed and good results were achieved.