Top 10 Voltmeter Brand & Manufacturers

What is a Voltmeter

A voltmeter is an electrical measuring instrument designed to determine the potential difference (voltage) between two points in an electric circuit. It is connected in parallel across the component or section of the circuit for which the voltage is to be measured. This allows it to measure the voltage drop without significantly affecting the current flow in the main circuit due to its high internal resistance.

History of Voltmeter

The concept of measuring electrical potential difference dates back to the early days of electrical research. Early voltmeters were simple electrostatic devices. In the 19th century, with the development of electromagnetic theory, more accurate and reliable voltmeters were developed. The first practical electromagnetic voltmeter was based on the galvanometer principle, where a coil placed in a magnetic field would deflect proportionally to the current flowing through it, which was related to the voltage being measured. As technology advanced, analog voltmeters became more refined, and later, digital voltmeters emerged, offering greater precision and additional features.

Purpose of Voltmeter

• Circuit Diagnosis: In electrical and electronic circuits, voltmeters are used to check if components are receiving the correct voltage. Malfunctioning devices can often be traced back to incorrect voltage supplies, and a voltmeter helps in quickly identifying such issues.
• Power Systems Monitoring: In power generation, transmission, and distribution systems, voltmeters are crucial for monitoring the voltage levels at various points. Maintaining proper voltage levels is essential for the efficient operation of electrical equipment and to prevent damage due to over - or under - voltage conditions.
• Educational and Research Purposes: In educational institutions and research laboratories, voltmeters are used to teach and study electrical principles, such as Ohm's Law and Kirchhoff's laws. They help in understanding how voltage behaves in different circuit configurations.

Principle of Voltmeter

Analog Voltmeter Principle: Most analog voltmeters are based on the galvanometer movement. A galvanometer is a sensitive instrument that deflects when a current passes through it. In a voltmeter, a high - value resistor (multiplier) is connected in series with the galvanometer. According to Ohm's Law (V = IR), the voltage being measured causes a current to flow through the series combination of the galvanometer and the multiplier. The deflection of the galvanometer is proportional to this current and is calibrated to directly read the voltage value.
Digital Voltmeter Principle: Digital voltmeters use an analog - to - digital converter (ADC). The input voltage is first converted into a digital signal by the ADC. The digital value is then processed by a microcontroller or other digital circuitry and displayed on a digital readout, usually in the form of numbers. The ADC measures the voltage by comparing it with a reference voltage and converting the difference into a digital code.

Features of Voltmeter

• Accuracy: High - quality voltmeters can provide very accurate voltage measurements, with some precision models having an accuracy of up to ±0.01% or better. This is crucial for applications where precise voltage readings are required, such as in calibration laboratories.
• Range Selection: Voltmeters typically have multiple voltage ranges. For example, a handheld digital voltmeter might have ranges from millivolts to several hundred volts. This allows for measuring a wide variety of voltage levels accurately.
• Input Impedance: As mentioned earlier, voltmeters have a high input impedance, usually in the mega - ohm range. This ensures that they draw minimal current from the circuit under test, reducing the impact on the circuit's normal operation.
• Data Logging and Display: Modern digital voltmeters often come with features like data logging, which allows them to record voltage readings over time. They also have clear and easy - to - read displays, some even with backlighting for use in low - light conditions.

Types of Voltmeter

• Analog Voltmeter: These use a pointer on a scale to indicate the voltage value. They are relatively simple in design and are still used in some applications where a quick visual indication of voltage is sufficient, such as in some industrial control panels. They can be further classified into moving - coil (D'Arsonval type) and moving - iron voltmeters based on the principle of operation of the measuring mechanism.
• Digital Voltmeter: Digital voltmeters display the voltage value as a numerical readout. They are more accurate, have a wider range of functions, and are easier to read compared to analog voltmeters. They are commonly used in laboratories, electronics repair shops, and in modern electrical and electronic equipment for monitoring voltage levels.[!--empirenews.page--]
• Multimeter (with Voltage - Measuring Function): A multimeter is a versatile instrument that can measure multiple electrical quantities, including voltage, current, and resistance. It combines the functionality of a voltmeter, ammeter, and ohmmeter. Multimeters can be either analog or digital, with digital multimeters being more popular due to their greater accuracy and additional features like auto - ranging.

Precautions for using Voltmeter

• Proper Connection: Always connect the voltmeter in parallel with the circuit element or section for which the voltage is being measured. Connecting it in series can cause incorrect readings and may damage the voltmeter or the circuit.
• Range Selection: Before taking a measurement, select an appropriate voltage range on the voltmeter. If the range is set too low for the actual voltage, it can damage the voltmeter. If the range is set too high, the reading may not be accurate. Many modern voltmeters have an auto - ranging feature, but it's still important to have an estimate of the voltage being measured.
• Over - voltage Protection: Some voltmeters have built - in over - voltage protection, but it's important to avoid exposing the voltmeter to voltages well beyond its rated maximum. High - voltage spikes can damage the internal components of the voltmeter.
• Calibration: Periodic calibration is necessary to ensure accurate readings. Follow the manufacturer's instructions for calibration intervals and procedures. Calibration can be done using a known voltage source or by sending the voltmeter to a professional calibration laboratory.

Things to consider when purchasing Voltmeter

• Accuracy Requirements: Determine the level of accuracy needed for your applications. If you are working in a precision - sensitive field like electronics manufacturing or calibration, you'll need a voltmeter with high accuracy. For general household or hobbyist use, a less accurate but more affordable model may be sufficient.
• Range: Consider the voltage levels you'll be measuring. If you need to measure both very low voltages (millivolts) and high voltages (hundreds or thousands of volts), look for a voltmeter with a wide range or one that allows for easy range selection.
• Type (Analog or Digital): Decide whether an analog or digital voltmeter is more suitable for your needs. Analog voltmeters can provide a quick visual indication of voltage trends, while digital voltmeters offer greater accuracy and additional features like data logging.
• Budget: Voltmeters are available in a wide price range. Set a budget and look for a model that offers the best combination of features and performance within your budget. Remember that more expensive models usually come with higher accuracy and more advanced features.

Terms of Voltmeter

• Voltage: The electrical potential difference between two points in a circuit, measured in volts (V). It represents the energy per unit charge available to move electrons through a circuit.
• Input Impedance: The resistance presented by the voltmeter to the circuit being measured. A high input impedance is desirable as it minimizes the current drawn from the circuit, reducing the impact on the circuit's operation.
• Range: The set of voltage values that a voltmeter can measure. Different ranges are provided to accommodate different voltage levels accurately.
• Accuracy: The degree of closeness of the measured voltage value to the true voltage value. It is usually expressed as a percentage of the full - scale reading or as an absolute value (e.g., ±0.1 V).