How to Test AC Voltage with a Multimeter

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Do you have any idea of what a multimeter is? Well, you most probably know it or have a rough what it is. A multimeter is a tool used to measure electricity, resistance, and voltage. Therefore, this device is very vital for all electrical activities, so you need to own one if you are a professional or a DIY enthusiast.

With this device, you will find making the repair as well as other similar duties easier than you would have ever imagined. Additionally, this machine is also easy to handle. If you have basic knowledge about it, you can make use of it across different electronic purposes, such as measuring the AC voltage. Therefore, measuring the AC voltage is very easy whenever you are using a multimeter.

So, how do you test an AC voltage with a multimeter? This is a vital question that you may be looking to have answered, and in this article, you will be taken through a step by step process on how this is done. Observing these procedures as required is crucial for you to be able to use the multimeter to test the AC voltage. Therefore, read through and get to learn about how to test an AC voltage using a multimeter. 

How do you measure AC voltage?

Most of you might be thinking that measuring AC voltage is difficult, but that is not the case. Typicality, for you to successfully measure AC voltage, you do not need to be an expert since there is nothing extraordinary about taking this measurement.

The only necessary skill is fundamental knowledge about taking this measurement, and you can always try this at your home using a standardised battery. After you connect your multimeter to your battery, the readings will be displayed on its screen. However, the results will not show on the screen of the multimeter in case there is a poor connection. Therefore, you first need to confirm that there is a proper connection to get an effective voltage measurement. The key elements for measuring voltage are;

  • Multimeter
  • Battery

Parts of a multimeter

The most vital elements of multimeter parts include; leads ports as well as the probes. These parts are usually made of top super quality ingredients such as top-notch material to give appropriate and durable readings. Thus, in case they are not finished with effective substances, they are likely to provide you with unsatisfactory results that may hinder your work. On the other hand, if the machine is not connected in the right manner to the right sources, the chances of it causing electrocution are very high.

Therefore, before purchasing a multimeter, you should do proper research before making up your mind to buy one. By doing this, you will be able to purchase the best quality of a multimeter which is made of quality materials.

Furthermore, you should also enquire about the materials you will be using as well as the type of probe you require. Thus, make sure you check the leads and ports before purchasing your multimeter, and doing thorough research will help you avoid incurring any unnecessary expenses, damages and errors.

Examine the leads

Before commencing on anything, you should make it a habit to examine all the key parts used in voltage measurements. After confirming that your multimeter is working well and is in good shape, you should then check on the leads.

Nevertheless, examining the leads should always be done manually and as you carry out the inspection, examine whether you can detect any visible malfunction or damage. As you do this, you should closely inspect the darkened parts, cracks or melted parts, and if everything is as expected, you can then go ahead and commence your work.

Test the leads

It is very crucial to test the state of the lead, and this you can achieve this by setting the multimeter in its resistance mode. Usually, the reading value displayed on the multimeter should be in ohms. Afterwards, connect ports with taps to the tips of the lead, and then check if everything is accurate, with the reading value on the multimeter expected to be 0.5 ohms or lower. Moreover, you must also take note that this test is vital before starting on the primary process to avoid any serious problem.

Understand the measurement readings

The AC voltage measurement usually varies from each other depending on the category of the AC system and how the power is distributed. Therefore, if you measure the AC voltage at different periods, you then are most likely going to get different results, and this will especially happen if the source of voltage is down than usual.

Steps of measuring AC voltage

  1. Switch of the power points of all plug points and circuits. This is for your safety reasons and also to avoid any accident from happening due to electrocution.
  2. Switch on your multimeter and set its energy on a high range to gauge the right position
  3. After that insert, the black colour probe lead to COM opening of the multimeter
  4. Check the point bearing the mark V and consequently sign and then insert the positive red colour lead probe into the opening.
  5. Since most multimeters are on automatic mode, if you measure your AC voltage, you should make sure you change it from the auto mode to a custom mode, and this you can do through the manual settings. Accuracy is usually needed, so you must select the required voltage range.

During these steps avoid some common mistakes such as; an incorrect connection which could lead to accidents, so it is crucial to make sure all the connections are correctly done for your safety. Additionally, keep repeatedly checking if the main leads are appropriately connected to the energy opening of the DMM and not any other sockets. While dealing with electrical tools, you need to be cautious to make the whole process successful. 


As you can see measuring AC voltage with a multimeter is not such a hassle, so you will be able to take the necessary measurements so long as you have some good basic knowledge about it. You should also make sure you have the proper skills on how to best use your multimeter to test AC voltage. This is important as it safeguards your safety as well as allows you to quickly know if the is an issue that needs fixing thanks to the multimeter reading.

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