What is a Multimeter?

The Electricity Forum
03/17/2024

What is a Multimeter?

A multimeter (MM) is essential for those working with electronics or electrical systems. It is a versatile instrument that combines several measurement functions into one unit, making it indispensable for electricians, technicians, and even DIY enthusiasts. This article will explore a multimeter's features, types of multimeters, and uses while answering some common questions about this indispensable tool.

WechatIMG1545.png

Multimeters come in two primary forms: digital (DMMs) and analog multimeter. DMMs have a digital display, making them easy to read and providing more accurate electrical measurements. In contrast, analog meters use a needle on a dial to indicate the measured value. While digital multimeters are generally more popular due to their precision and ease of use, analog MMs can be useful for observing trends or changes in measurement.

One of the primary functions of a multimeter is to measure voltage. Voltage measurements can be made on both alternating current (AC) and direct current (DC) sources. To do this, the multimeter is connected to the circuit under test using red and black test probes. Therefore, selecting the appropriate measuring range and observing safety precautions when dealing with high voltages is essential.

In addition to voltage, multimeters can measure current and resistance. Current measurement involves connecting the multimeter in series with the circuit under test, while resistance measurement is performed by connecting the multimeter across the component or circuit. Some multimeters can also measure other quantities, such as capacitance and frequency, further expanding their versatility.

Multimeters typically include a continuity test function, which is useful for checking if there is a complete electrical connection between two points in a circuit. This function works by sending a small current through the circuit and detecting if the current flows without interruption.

The accuracy of a multimeter's measurements depends on its input resistance, which determines how much it will disturb the circuit under test. Therefore, the higher input resistance is desirable, as it minimizes the impact on the measured circuit. Field-effect transistors (FET) and vacuum-tube voltmeters (VTVMs) achieve high input resistance by amplifying a tiny current before displaying it on the meter.

Choosing the best multimeter for your needs depends on various factors, including the required measurement functions, accuracy, and budget. Auto-ranging multimeters automatically select the appropriate measuring range for the measured quantity, making them more user-friendly than manual-ranging multimeters.

Safety precautions should always be observed when using a multimeter. These include using the correct measuring range, avoiding contact with live circuits, and using insulated test probes. In addition, proper maintenance and calibration of the multimeter are essential for ensuring accurate measurements over time.

A multimeter is a versatile tool that combines the functions of an ammeter, ohmmeter, and voltmeter, among others. It enables users to measure voltage, current, resistance, and other electrical quantities in a variety of power supply applications. By understanding the differences between analog and digital multimeters, their various functions, and the importance of safety precautions, users can make informed decisions about which multimeter is best suited to their needs.

Statement: Respect the original, good articles worth sharing, if there is infringement please contact delete.

The Electricity Forum

Electricity Forum publishes Electricity Today T&D Magazine and Intelligent Power Today Industrial Electrical Magazine. We publish electrical technical handbooks and associated digital magazine advertising supplements.

Working Voltage in Power System
Working Voltage in Power System
Working VoltageThe term "working voltage" refers to the maximum voltage that a device can withstand without sustaining damage or burning out, while ensuring the reliability, safety, and proper operation of both the device and associated circuits.For long-distance power transmission, the use of high voltage is advantageous. In AC systems, maintaining a load power factor as close to unity as possible is also economically necessary. Practically, heavy currents are more challenging to handle than hi
Encyclopedia
07/26/2025
What is a Pure Resistive AC Circuit?
What is a Pure Resistive AC Circuit?
Pure Resistive AC CircuitA circuit containing only a pure resistanceR(in ohms) in an AC system is defined as a Pure Resistive AC Circuit, devoid of inductance and capacitance. Alternating current and voltage in such a circuit oscillate bidirectionally, generating a sine wave (sinusoidal waveform). In this configuration, power is dissipated by the resistor, with voltage and current in perfect phase—both reaching their peak values simultaneously. As a passive component, the resistor neither
Edwiin
06/02/2025
What is a Pure Capacitor Circuit?
What is a Pure Capacitor Circuit?
Pure Capacitor CircuitA circuit comprising only a pure capacitor with capacitanceC(measured in farads) is termed a Pure Capacitor Circuit. Capacitors store electrical energy within an electric field, a characteristic known ascapacitance(alternatively referred to as a "condenser"). Structurally, a capacitor consists of two conductive plates separated by a dielectric medium—common dielectric materials include glass, paper, mica, and oxide layers. In an ideal AC capacitor circuit, the current
Edwiin
06/02/2025
Resistance Switching in a Circuit Breaker
Resistance Switching in a Circuit Breaker
Resistance SwitchingResistance switching refers to the practice of connecting a fixed resistor in parallel with the contact gap or arc of a circuit breaker. This technique is applied in circuit breakers with high post-arc resistance in the contact space, primarily to mitigate re-striking voltages and transient voltage surges.Severe voltage fluctuations in power systems arise from two main scenarios: interrupting low-magnitude inductive currents and breaking capacitive currents. Such overvoltages
Edwiin
05/23/2025
Inquiry
Download
IEE-Business is dedicated to serving the personnel in the global power industry.
Join IEE-Business, not only can you discover power equipment and power knowledge, but also canhnd like - minded friends!