How to Measure AC Current Using Multimeter?

What is a multimeter?

A multimeter, also known as a volt-ohm meter (VOM), is a measuring instrument used to measure different electrical parameters such as voltage, current, and resistance in electrical circuits. It typically has a digital or analog display and can be used to test batteries, fuses, electrical outlets, switches, and other electrical components. However, let’s see how to measure ac current using multimeter in a systematic way.

Why do we use a multimeter?

We face a question what does a multimeter measure? Multimeters are used for a variety of purposes in electrical and electronic work. Here are some reasons why we use multimeters:

Measuring voltage

Multimeters are used to measure the voltage across different components in a circuit. This helps in determining whether the voltage is within the expected range, which can help diagnose issues with the circuit.

Measuring current

Measuring current is important in determining the power consumption of a device, and in diagnosing problems with electrical components. Multimeters can be used to measure both AC and DC currents.

Measuring resistance

Multimeters can be used to measure the resistance of electrical components, such as resistors, and to diagnose issues with circuits.

Continuity testing

Multimeters can be used to test for continuity in a circuit, which helps in locating breaks or faults in the circuit.

Diagnosing electrical issues

Multimeters are an essential tool for electricians, engineers, and technicians in diagnosing and repairing electrical problems in devices and circuits. The multimeters are versatile tools that can measure different electrical parameters and are used in a variety of electrical and electronic applications.

How to measure ac current using a multimeter?

The multimeter is the best electronic device to measure AC current, DC current, and some other electrical quantities. However, to measure AC current using a multimeter, follow these steps:

• Make sure the multimeter is set to measure AC current. Look for the symbol that represents AC current (usually a sine wave with a dashed line above it). Some multimeters have a separate dial setting for AC current, while others have a button to switch between AC and DC current measurement.
• Turn off the power to the circuit you want to measure.
• Insert the black multimeter probe into the COM jack and the red probe into the VΩmA jack.
• Connect the probes to the circuit. Place the black probe on the negative side of the circuit, and the red probe on the positive side.
• Turn on the power to the circuit.
• Read the measurement on the multimeter display. Make sure you take note of the unit of measurement (usually amps or milliamps).
• Turn off the power to the circuit and disconnect the probes from the circuit.

Be sure to follow proper safety precautions when working with electrical circuits. Avoid touching the metal parts of the probes, and make sure the multimeter is set to the correct range before taking a measurement.

What are the types of a multimeter?

Basically, we get two types of multimeter analog multimeter and digital multimeter. On the other hand, there are several types of multimeters available, each designed for specific applications. Here are some common types of multimeters:

Analog multimeters

These are the oldest type of multimeters and use a moving needle to indicate the measured value. They are simple to use but less accurate than digital multimeters.

Digital multimeters (DMM)

These multimeters use digital displays to show the measured value. They are more accurate than analog multimeters and are commonly used in modern applications.

Clamp multimeters

These multimeters are used to measure AC current without the need to disconnect the circuit. They work by clamping around the wire being measured and are useful for measuring current in high-power circuits.

Automotive multimeters

These multimeters are designed specifically for use in the automotive industry. They have additional features for measuring automotive-specific parameters like RPM, temperature, and battery voltage.

Benchtop multimeters

These are larger, more advanced multimeters designed for use in laboratory settings. They offer higher accuracy and precision and can measure a wider range of parameters.

Wireless multimeters

These multimeters can be connected to a Smartphone or tablet, allowing for wireless monitoring and data logging.

Each type of multimeter has its unique features and applications. It's important to choose the right multimeter for your specific needs to ensure accurate and reliable measurements.

Is there any option to measure voltage, current, and resistance instead of a multimeter?

Multimeters are the most common and convenient tool for measuring voltage, current, and resistance, but there are other tools that can be used to measure these parameters as well. Here are some alternatives:

Voltage testers

These are simple devices that can be used to test the presence of voltage in a circuit. They typically use LEDs or an audible alarm to indicate the presence of voltage.

Ammeters

Ammeters are devices that are specifically designed to measure electric current. They can be used in conjunction with a voltage source and a known resistance to measure current in a circuit.

Ohmmeters

Ohmmeters are devices that are designed to measure electrical resistance. They typically use a known voltage source and measure the resulting current flowing through the circuit to determine the resistance.

Oscilloscopes

Oscilloscopes are devices that can be used to measure the voltage over time, which can be used to determine the frequency, amplitude, and other characteristics of an electrical signal. While these tools can be used to measure electrical parameters, they may not be as convenient or accurate as a multimeter, and may not offer the same range of measurement capabilities. It's important to choose the right tool for the specific application to ensure accurate and reliable measurements. 

Final Thought 

The multimeter is a crucial and more useable electronic device to measure the electrical properties. Multimeters can be used by electricians, engineers, and technicians to troubleshoot and repair electrical circuits and devices. They come in different types and models, with different levels of accuracy and features, and can be used for a variety of applications. Multimeters have two probes, one for the positive and the other for the negative side of the circuit, which are connected to the device being tested. The device then measures the electrical quantity and displays the results on the screen.