What are the differences between an analog multimeter and a digital multimeter?
A multimeter is an electrical measuring instrument used to measure electrical parameters such as voltage, current, and resistance. Not all multimeters are the same. Different multimeters vary in size, precision, accuracy, and the parameters they can measure. Multimeters are mainly used by electricians, engineering students, and hobbyists to troubleshoot electrical equipment and circuits. There are two main types of multimeters: the analog multimeter and the digital multimeter.
Analog Multimeter
The analog multimeter is the oldest type of multimeter. It has a needle that rotates along a scale, but it is difficult to read. Its advantages are that it is inexpensive and sensitive. An analog multimeter is more sensitive than a digital multimeter and can even detect minute changes in the reading.
An analog multimeter is made of a coil placed between two permanent magnets, with a needle on top of the coil. When current passes through the coil, the coil generates a magnetic field that interacts with the magnetic field of the permanent magnets, causing it to rotate. As the coil rotates, the needle moves along the scale. The angle of rotation of the coil depends on the amount of current flowing through the coil. Therefore, an analog multimeter is also called a galvanometer. It has a very low resistance, making it more sensitive than a digital multimeter. However, it should be noted that full-scale deflection (FSD) should be avoided. When the current exceeds the range of the coil's deflection, the coil will start to burn, resulting in damage to the meter.
Digital Multimeter
A digital multimeter is an instrument that can measure various parameters and display them on an LCD screen. Different from an analog multimeter, a digital multimeter displays the measurement results in a digital calculation manner, so it is easier to read the measurement results. But on the other hand, an analog multimeter can display the reading without any calculation, so it has a fast response time.
A digital multimeter has an LCD, a rotating dial, and multiple ports. The dial includes an internal circuit that is connected through a concentric ring. The dial knob is used to activate the circuit for specific measurements. A digital multimeter has an embedded microprocessor to calculate the reading. However, the input voltage or current is in analog form. Therefore, an ADC (Analog-to-Digital Converter) is included to convert the reading and display it on the LCD screen. Unlike the needle scale on an analog multimeter, the LCD makes the measurement results easy to read. In addition, a digital multimeter has overload protection when the measurement is out of range.
