Which type of voltmeter is specifically designed to measure electrostatic voltage?

The correct response is the electrostatic voltmeter, which is a specialized instrument designed specifically for measuring electrostatic voltages. Unlike standard analog or digital voltmeters, which can measure a wide range of electrical voltages in various applications, an electrostatic voltmeter operates based on the principles of electrostatics. It measures the voltage present without drawing significant current from the circuit being tested, which is crucial when dealing with high-impedance electrostatic fields.

This type of voltmeter uses an internal capacitor to measure voltage by detecting the electric field around a charged object. It provides accurate readings of low-level voltages found in electrostatic applications, such as in some electronic components and processes. The unique functionality of the electrostatic voltmeter allows it to operate effectively in scenarios where traditional voltmeters may not provide an accurate or reliable measurement due to their inherent loading effects on high-impedance circuits.

Thus, the electrostatic voltmeter stands out as the most appropriate choice for measuring electrostatic voltages. Other types of voltmeters, although they have their specific use cases, do not cater to this specialized need as effectively as the electrostatic voltmeter does.