Derivative action (referred to by the letterd) measures and responds to the rate of change of process signal, and adjusts the output of the controller to minimise overshoot.
微分动作(字母d表示)测量并对过程信号变化率进行反应，调整控制器的输出以达到最小的突出峰。
3
For each of them there are four choices marked A, B, C and D. You should decide on the best choice and mark the corresponding letter on Answer Sheet 2 with a single line through the centre.