Ammeter: Definition, Types, and Symbol

An ammeter is a basic tool used in electrical circuits to measure the flow of current electricity, which helps us know how much current there is, that is, how much charge passes through a wire per unit. Whether it is alternating current (AC) or direct current (DC), understanding how an ammeter works and how to use it is very important for us to accurately measure current in a circuit.

In this article, let’s learn some basics about ammeters, including:

• The ammeter’s definition

• Types and symbol

• Ammeter vs voltmeter

What is an Ammeter?

In simple terms, an ammeter is an instrument used to measure current (charge flow) in a circuit. The unit of current is the ampere, often abbreviated as A. The ammeter works by connecting in series with circuit components to measure the magnitude of current. By measuring current, ammeters provide important information about circuit performance and safety.

What does an Ammeter Measure?

As we have already explained, an ammeter is a device that measure current electricity- which is the flow of electric charge in a circuit. More specifically, it measures the amount of positive charge (or, depending on the direction of the current, negative charge) passing through the conductor every second. Ammeters can be used to measure AC and DC, but each type of current is measured differently.

• In a direct current circuit, current flows in one direction, meaning that the positive charge flows in one direction.

• In an alternating current circuit, current periodically changes direction, with positive and negative charges flowing in opposite directions respectively.

In both cases, the reading provided by the ammeter reflects the amount of current electricity passing through the circuit.

Ammeter Symbol

The ammeter symbol is usually shown in the circuit diagram due to the use of an ammeter to measure current in the circuit. The ammeter symbol is a circle with an “A” in it, where the “A” stands for ampere. The connection of the ammeter to the circuit can also be seen as extended lines in some circuit diagrams. Always connect an ammeter in series to the component for which it measures the current.

Types of Ammeters

With the development of technology and demand, the types of ammeters have also diversified. The following table shows the four ammeters commonly used in the electronics industry, as well as their respective characteristics and application scenarios.

Ammeter VS. Voltmeter

The ammeter and voltmeter are both vital tools in electrical measurement, but they have different roles in electrical work. Understanding the difference between the two instruments is a must for everyone who wants to learn electrical work.

• An ammeter is used to measure current (in amperes) and must be connected in series to the component whose current needs to be measured. The current flows through the ammeter, and the instrument registers the magnitude of the current.

• A voltmeter is used to measure the voltage (potential difference) between two points in a circuit. Unlike an ammeter, a voltmeter should be connected in parallel with the component being tested.

Conclusion

Ammeters are crucial in current measurement, helping to precisely monitor circuit behavior. Modern digital ammeters offer higher accuracy and easy-to-read displays. By mastering their principles and usage, you can more effectively perform electrical diagnosis and troubleshooting.