Digital voltmeters and ammeters are essential measuring instruments used to check voltage and current in electrical and electronic systems. A digital voltmeter measures the potential difference between two points, while a digital ammeter measures the amount of current flowing through a circuit. Unlike analog meters that use moving pointers, digital meters use electronic circuits and a digital display to show accurate readings instantly. They are easier to read, faster, and free from parallax errors.
A digital voltmeter works by converting the input voltage into a digital signal using an analog-to-digital converter (ADC). The ADC samples the voltage, processes it, and sends the digital output to the display unit. This digital representation provides a clear numeric value of voltage, making it ideal for industrial, laboratory, and control panel applications where precision is critical. These voltmeters often have ranges like 0–200V, 0–500V, or more, depending on the measurement requirement.
A digital ammeter operates on a similar principle but measures current instead of voltage. It usually contains a shunt resistor, a small resistance placed in series with the circuit. As current flows through the resistor, a small voltage drop develops across it. This voltage is then fed to the ADC, converted into a digital value, and displayed as current in amperes. The reading is quick, stable, and highly accurate.
In industrial automation systems, digital voltmeters and ammeters are widely used in control panels to continuously monitor supply lines, detect faults, and prevent overloads. Brands like Selec and Autonics manufacture reliable panel meters that help engineers maintain efficiency and safety in electrical setups. These meters are compact, energy-efficient, and designed for long-term performance, making them an important part of any electrical monitoring system.