 Lippmann electrometer

The Lippmann electrometer is a type of sensitive instrument used to measure electric potential (voltage). It is based on the principle of measuring the height of a liquid column in a capillary tube, where the liquid is typically mercury. The device is named after the physicist Walter Lippmann. The basic working principle involves the following steps: 1. **Mercury Column**: The Lippmann electrometer uses a column of mercury contained in a glass tube.