Abstract：The interlock of linear accelerators can be divided into three categories including primary interlock, secondary interlock,
and dose interlock. This paper focused on the failure of secondary dose interlock UDR1 and UDR2 of the Varian C series linear
accelerator, introduced in detail the causes of the failure and how to resolve it quickly. According to the random drawing of the
accelerator and the principle of ray generation, the relevant indicators were detected by using oscilloscope and multimeter. Then, the
difference between the results and the normal value were compared, and the fault was analyzed in detail. Finally, the fault was solved
by replacing the relay K2 and the signal line in the side connected AFC system. We hope that the analysis of maintenance ideas can
provide reference for peers.
严维江，周杰. 瓦里安C系列直线加速器次要剂量连锁的故障判断与维修[J]. 中国医疗设备, 2021, 36(6): 179-182.
YAN Weijiang, ZHOU Jie. Fault Diagnosis and Maintenance of Secondary Dose Interlock of
Varian C Series Linear Accelerator. China Medical Devices, 2021, 36(6): 179-182.
