The steady counting rates of neutron in reactor are measured by a conventional instrument(the start-up devices)to calibrate reactivity worth of a control rod.
利用常规仪器（堆控制室中的启动装置）测得反应堆中稳定的中子计数率来刻度控制棒的反应性当量。
2
When the workpiece presses and pushes the touch rod, the touch rod and the swinging arm can swing to a counting position;