探测器(detector)，是观察 、记录粒子的装置 ，核物理和粒子物理实验研究中不可缺少的设备。探测器可分为两类：计数器和径迹探测器。
Detector is a device for observing and recording particles. It is an indispensable device in the research of nuclear physics and particle physics experiments. Detectors can be divided into two categories: counters and track detectors.
金属探测器利用电磁感应的原理，利用有交流电通过的线圈，产生迅速变化的磁场。
The metal detector uses the principle of electromagnetic induction and coils with alternating current to generate rapidly changing magnetic fields.