A Voltmeter is a measuring instrument that is used to measure the potential difference between two nodes and the potential difference is measured in terms of volts. So we can say voltmeter is a device that is used to measure the voltage of a circuit.
Few of the voltmeters are designed to use only on DC circuits while a few are used in AC circuits. There are special types of voltmeters, which are used to measure the radio frequency voltage. There are two types of voltmeters available.
Table of Contents
- Analog vs Digital Voltmeter
- How to use a voltmeter?
- How to use a voltmeter to check the voltage?
- Application of Voltmeter
- How to test the light switch using a multimeter?
- How to use a multimeter on a car?
- Advantages and disadvantages of Voltmeter
- Tips to choose a Voltmeter
Analog vs Digital Voltmeter
The Analog voltmeter will move the pointer as per the circuit voltage. The output signal representation is done by using potentiometric deflection. It is a less sensitive device. In this type of voltmeter programming can not be done so we need to define the range first to do any type of measurement. It is mainly used to measure voltage, current, and resistance. The cost of an analog voltmeter is not much as compare to digital voltmeter but the size of these type voltmeter is large.
whereas the Digital voltmeter measures the voltage and converts into digital value so analog to digital converter is required for that. It displays the voltage in numeric form due to that, the accuracy of measurement is high. It can be programmed so there is no need to define any range before measurement. These are very handy devices due to their small size and design. But the price of a digital voltmeter is higher than analog voltmeter due to its complicated construction of electronic and logic components. With the digital voltmeter, we can measure current, voltage, resistance, capacitance and inductance as well.
How to use a voltmeter?
Here is the step by step procedure to be followed by users who are using a voltmeter:
- Plug the throngs of the voltmeter into the circuit or meter, whose voltage you would like to check or measure. The red color probe is positive while the black color is negative.
- Turn ON the selector dial or switch to the type of measurement you want to measure. For measuring direct current, i.e., in a battery, you need to use DCV. To measure the AC, i.e., alternating current in the wall outlet, you need to use ACV.
- Select the settings of the range. The dial will be having options ranging from 5 to 1000. These options you can see on the DCV end and 10 to 1000 on the ACV end. You need to set the top end of the voltage you want to read. However, it is important to note that not all voltmeters will be having the same kind of settings.
- Now, it is time for you to Turn ON the meter.
- You need to hold the probes, i.e. positive and negative probes on both sides and touch the red side of the probe to the DC circuit or to the AC circuit and the black probe to the other side of either of these circuits.
- Read the voltage that is displayed either on the analog or digital signal.
You need to follow the above steps to accurately and quickly measure the voltage of any circuit.
How to use a voltmeter to check the voltage?
The voltmeter has to be connected in parallel to the circuit in which you want to measure the voltage. A voltmeter is connected in parallel because it is constructed to have high resistance. If you connect a voltmeter in series, then with high resistance, the amount of current flows in the circuit will be zero, meaning that it is an open circuit. If you connect a voltmeter in parallel, the load impedance will come in parallel with the resistance in the voltmeter, and this combination will give higher impedance than what the load posses.
Application of Voltmeter
This is a handy tool that is used for homeowners and professionals to measure the voltage in a circuit and detect problems in electrical wiring.
For instance, if you have turned ON the fan and observed that the fan is not rotating, then there would be many reasons for the fan not to work. The main reason would be a broken fan. If you want to confirm whether the outlet is receiving the electricity or not, you can connect the voltmeter to measure the voltage of the outlet. If the voltage is not, 120 volts, it means that the outlet has an issue.
As the name suggests, it is used to measure voltage. There are a few models of a voltmeter that are used to measure resistance and current. These are popularly called as Multimeters. These are available in analog and digital models.
You can use a voltmeter for testing batteries and check whether or not the battery is charged.
How to test the light switch using a multimeter?
If you want to check whether or not the light switch is working properly or not, you can check it in various ways.
One of the best ways to check whether the power is flowing through the switch or not using the voltage meter also known as a voltmeter. You should be able to read the voltage when you are moving the switch up and down. You need to ensure to check the bulb prior to checking the voltage of it.
There is a wide range of voltage meters available in the market. You need to pick the best one that fits your needs to test the light switch in your home or commercial places. This is the testing tool that is used by the electrician to check whether the switch is working or not. This inexpensive tool will sense whether or not the current is passing through the switchboard to which the light is connected to.
To measure the voltage, you need to place the probes of the voltmeter to the two ends of the switch. You need to be very cautious while performing the test. It is highly recommended to wear personal protective equipment to avoid electrocution.
This test is carried out when the power of the switch is turned ON. The two leads between which the switch is connected will light up the light when the current is sensed in the circuit. This may not show accurate results when carrying out a light switch test.
The key problem that is encountered is that the light that is present in the tester will be acting as a bridge for the circuit when is switched OFF. This will let the current to flow through the filament of the tester. The current will be shown even when the switch is off and in ON condition making you think that the switch is malfunctioning.
The best way to test whether or not the light switch is working or not is to remove the filament in the light bulb and then perform the test. When you remove the light bulb, the tester will not light up when the switch is ON or in OFF position. This will light up only when the switch is ON.
The above test is conducted to test the light switch using a multimeter.
How to use a multimeter on a car?
You can use a multimeter to check the functionality of the circuit in the car. To check circuit functionality, you need to connect the two prongs to the battery terminals to check the voltage reading.
If the engine and alternator of the car are working fine, the voltage should increase with the increase in speed.
If it is not increasing with the speed that means there is some issue with the alternator.
So multimeter is a very useful device for testing the car circuit functionality.
Advantages and disadvantages of Voltmeter
Advantages of voltmeter
- It is programmed and is easy to control with the help of the system
- Has a wide range of designs
- Offer good stability
- Sturdy and give an accurate reading
- Offer better resolution. It also allows you to read even 1v input range.
- Work at a high speed
- Take the reading very briskly
Disadvantages of voltmeter
- Expensive, when you need the voltmeter with many bells and whistles
- The speed at which it operates is limited due to the digitized circuit
- Hard to detect the spikes in transient voltage
Tips to choose a Voltmeter
With overwhelming options of voltmeter models available in the market, it is challenging for the people to buy the best multimeter for home use that offers high durability and reliability. More importantly, that is cost-effective and serves the purpose.
This is the first and foremost factor to consider while buying an analog or a digital voltmeter. You can get a basic to high-priced voltmeters. However, the higher-priced ones are more durable and give accurate readings compared to low priced ones. In addition, expensive ones are more efficient and simple to use. You need to check the features of two to three voltmeters of various brands side by side and pick the right one that is offering you with the features you want and at the best price.
A basic voltmeter is used to measure the voltage in the circuit. There are a few voltmeters that are also used to carry out a battery test, diode test, transistor test and offer many other features over basic voltmeters.
Display counts and digits:
This plays a critical role in buying a voltmeter. You need to pick the voltmeter that offers many displays counts to get an accurate value.
The voltage that is passed through the voltmeter depends on the source to which it is connected. When you are dealing with high voltage circuits, you need to make sure that the voltmeter you are using is not harmful and perilous.