Electroscope whether an object is charged with electricity and a rough estimate of the size of the equipment testing, typical structure as shown on the left. When contacted electroscope test object top conductors, the charge itself will spread to the foil inside the bell jar. Since like charges repel each other with the foil will automatically separate sheets angled. According to the two foil sheets angled size can estimate the size of the object with electricity. In fact, this is the foil suffered electric force on the foil of the same name, including the attractiveness of the inner wall of the charge repulsion and utensils synonym charge. If the glass in order to use a metal box shield electrostatic, metal rods and utensils out leads in order to measure the potential difference between two points, increasing the quantization scale so that the results, it can be transformed into a more precise electroscope electrometer