This instrument is used for static electricity experiments. It can measure the potential difference between two charged objects; check whether the object is charged; check whether the object is negative, check the insulation of the object, and perform inductive electrification tests. 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 earth's electric potential is zero, the electric potential of each charged body can be measured with an electroscope. When checking the charge of the object, the electroscope ball can be used to first the object to be inspected, and then transfer the obtained electric charge to the electroscope metal rod, or the metal rod can be directly contacted with the object. The easiest way to check the insulation of an object is to ground the object (touch it with your hands), and another point of the object is inwith the charged electroscope metal rod. Observe the pointer of the electroscope. If the pointer returns to zero soon, The tested object is a conductor, otherwise it is an insulator. It is best to wipe the insulating sleeve with a soft dry cloth before use, because dust and moisture are often affected, which can damage the insulation performance. When the instrument is severely affected by moisture, it is best to use it after drying.