1. This instrument is used for experiments with static electricity. It can measure the potential difference between two charged objects; check whether the object is charged; verify if the object is negative, inspect the insulation of the object, and conduct tests on inductive electrification. 2. When measuring the potential difference between two charged bodies, connect the metal shell of the electroscope to one charged body, connect the metal rod to the other charged body, and generally ground the shell. If the electric potential of the Earth is zero, the electric potential of any charged body can be measured with an electroscope. 3. When checking the charge of an object, the electroscope ball can be used to first contact the object under investigation and then transfer the acquired electric charge to the metal rod of the electroscope, or the metal rod can be directly brought into contact with the object. 4. The simplest way to check the insulation of an object is to ground the object (by touching it with your hands) and bring another part of the object into contact with the charged metal rod of the electroscope. Observe the pointer of the electroscope. If the pointer soon returns to zero, the tested object is a conductor; otherwise, it is an insulator.