故障现象 :病人头部扫描时伪影严重 ,体部扫描时伪影稍微好一点。伪影灰白相间、宽纹。分析与检修 :早上开机时 ,做空气校正正常 ,做几个病人后 ,就出现上述故障现象。开始几天里 ,出现伪影后 ,做空气校正后能恢复正常 ,且能维持一天或半天 ,但随着时间的推移 ,故障出现频率越 Symptoms: When the patient’s head scans, the artifacts are serious. The artifacts are slightly better when the body scans. Artifact gray and white, wide pattern. Analysis and Maintenance: In the morning when the machine is turned on, air calibration is normal. After several patients, the above failure phenomenon occurs. In the first few days, after the occurrence of artifacts, air correction can be returned to normal and can be maintained for one or a half days. However, with the passage of time, the frequency of failures becomes more frequent.