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Electrometer vs. Voltmeter — What's the Difference?

By Fiza Rafique & Maham Liaqat — Updated on March 15, 2024
An electrometer measures electrical charge with high sensitivity, while a voltmeter measures electrical potential difference, or voltage, between two points.
Electrometer vs. Voltmeter — What's the Difference?

Difference Between Electrometer and Voltmeter


Key Differences

Electrometers are highly sensitive instruments designed to detect and measure electric charges, even those as small as a single electron charge. On the other hand, voltmeters are used to measure the electrical potential difference, commonly known as voltage, between two points in an electrical circuit.
The primary function of an electrometer is to measure static electric charges without discharging them, making it ideal for experiments in physics where minimal interaction with the measurement instrument is crucial. Whereas voltmeters, which can be either analog or digital, are essential tools for electricians and engineers for troubleshooting and designing electrical circuits by measuring voltage.
Electrometers operate by detecting the effect of an electric charge on a mechanical system or electronic field, which can then be measured with high precision. In contrast, voltmeters measure voltage by allowing a small amount of current to pass through the meter from one point in the circuit to another, and the voltage is determined based on the current and the known resistance within the meter.
Due to their high sensitivity, electrometers can also be used in specialized applications such as radiation dosimetry, where they measure ionization charges resulting from radiation, reflecting the wide range of their applications beyond simple charge measurement. Voltmeters, while not suitable for measuring static charges or very low currents directly, are versatile in their application across various types of electrical and electronic work, from simple battery checks to complex circuit diagnostics.
Both electrometers and voltmeters are crucial in their respective domains: electrometers for research and applications requiring high sensitivity to electric charge, and voltmeters for a broad range of applications in electrical engineering and electronics, emphasizing their complementary roles in science and industry.

Comparison Chart


Electrical charge
Electrical potential difference (voltage)


High, can measure tiny charges
Variable, depending on the design and range

Primary Use

Research, static charge measurement
Electrical circuit troubleshooting and design

Operation Principle

Detection of charge effect on mechanical or electronic system
Measurement of voltage through known resistance


Physics experiments, radiation dosimetry
Electrical and electronic work, circuit diagnostics

Compare with Definitions


High Sensitivity.
The laboratory's electrometer can detect charges as small as those produced by single electrons.


Electrical Potential Difference.
To diagnose the circuit issue, we measured the voltage drop across the resistor with a voltmeter.


Minimal Interaction.
For accurate radiation dosimetry, the electrometer measures ionization without disturbing the field.


Versatile Application.
From simple battery checks to complex circuit analysis, a voltmeter's applications are vast.


Versatile Research Tool.
Electrometers are crucial in experiments requiring precise charge measurements.


Measures Voltage.
Using a voltmeter, we determined the battery's health by measuring its output voltage.


Detects Tiny Electric Charges.
The electrometer's sensitivity makes it invaluable for detecting minute charges in scientific research.


Analog and Digital Types.
Whether analog or digital, a voltmeter is a staple in every electrician's toolkit.


Static Charge Measurement.
We used an electrometer to measure the static charge accumulated on the surface.


Troubleshooting Electrical Circuits.
The voltmeter indicated a much lower voltage than expected, pointing to a possible short circuit.


An electrometer is an electrical instrument for measuring electric charge or electrical potential difference. There are many different types, ranging from historical handmade mechanical instruments to high-precision electronic devices.


A voltmeter is an instrument used for measuring electric potential difference between two points in an electric circuit. It is connected in parallel.


An instrument used for measuring voltage.


An instrument for measuring electric potential differences in units of volts.


A device used to detect and measure static electricity; an electroscope.


An instrument for measuring electric potential in volts.


A precision voltmeter that draws almost no current from the circuit.


An instrument for measuring in volts the differences of potential between different points of an electrical circuit.


An instrument for measuring the quantity or intensity of electricity; also, sometimes, and less properly, applied to an instrument which indicates the presence of electricity (usually called an electroscope).


Meter that measures the potential difference between two points


Meter to measure electrostatic voltage differences; draws no current from the source

Common Curiosities

What does a voltmeter measure?

A voltmeter measures the electrical potential difference, or voltage, between two points in an electrical circuit.

Are voltmeters necessary for all electrical work?

While not every task may require a voltmeter, they are essential tools for diagnosing, designing, and troubleshooting electrical circuits, making them indispensable in most electrical work.

What is an electrometer used for?

An electrometer is used for measuring static electric charges with high sensitivity, ideal for physics research and specialized applications like radiation dosimetry.

Can an electrometer be used in place of a voltmeter?

Due to their different functions and sensitivities, an electrometer cannot typically be used in place of a voltmeter for everyday electrical engineering and circuit diagnostic tasks.

How do electrometers and voltmeters differ in their operation?

Electrometers measure electrical charge by detecting its effect on a mechanical system or electronic field, while voltmeters measure voltage through a known resistance by allowing a small current to flow.

Can a voltmeter measure electrical charge?

A voltmeter is not designed to measure electrical charge directly, especially static charges or very low currents, due to its principle of operation.

Why is sensitivity important in an electrometer?

Sensitivity is crucial in an electrometer to accurately detect and measure very small electric charges, which is essential for certain scientific experiments and applications.

How does a digital voltmeter work?

A digital voltmeter measures voltage by converting the analog electrical potential difference into a digital number using an analog-to-digital converter, displaying the voltage on a digital screen.

What advancements have been made in electrometer technology?

Advances in electrometer technology include improved sensitivity, the ability to measure extremely low current levels, and enhanced interface options for data collection and analysis, expanding their application range.

Can electrometers measure both positive and negative charges?

Yes, electrometers can measure both positive and negative charges, making them versatile tools for a wide range of scientific research.

What is the principle behind a voltmeter's measurement?

The principle behind a voltmeter's measurement is Ohm's law, which relates voltage, current, and resistance, allowing the voltmeter to determine voltage based on the current flowing through a known resistance.

How do you safely use a voltmeter in an electrical circuit?

To safely use a voltmeter, ensure it's set to the correct measurement range, observe proper polarity, and never connect it to a circuit when it's configured to measure current or resistance.

What makes electrometers suitable for radiation dosimetry?

Electrometers are suitable for radiation dosimetry because they can measure the ionization charge produced by radiation without significantly disturbing the field, providing accurate dosimetry readings.

How has the use of voltmeters evolved over time?

The use of voltmeters has evolved from simple analog designs to sophisticated digital models with high accuracy, portability, and the ability to measure a wide range of voltages, enhancing their utility in modern electrical engineering.

What role do electrometers play in environmental science?

In environmental science, electrometers can play a role in measuring electric charges associated with atmospheric phenomena, pollution detection, and studying the effects of radiation on the environment, contributing to research and monitoring efforts.

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Author Spotlight

Written by
Fiza Rafique
Fiza Rafique is a skilled content writer at, where she meticulously refines and enhances written pieces. Drawing from her vast editorial expertise, Fiza ensures clarity, accuracy, and precision in every article. Passionate about language, she continually seeks to elevate the quality of content for readers worldwide.
Co-written by
Maham Liaqat

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