What Does ACV Stand for on a Multimeter

What Does ACV Stand for on a Multimeter

If you have electrical problems in your home, you can't go wrong with a licensed electrician. However, if you decide to take a do-it-yourself approach to electrical maintenance, you can buy a digital multimeter for a few euros.

A multimeter is not a solution, but it will help you measure the voltage, current and resistance of any circuit in your home. They are inexpensive ($10 is enough to buy a multimeter that offers the basic functions) and fairly easy to use, although they may seem intimidating at first. There are some symbols on the multimeter dial that you don't see every day.

Understanding the multimeter dials

Your basic multimeter has a dial that indicates the type of measurement you want to make. The voltage reading is called DCV for direct current and ACV for alternating current. The former can be used to test batteries, while the latter can be used to test sockets, appliances and electronics.

When measuring resistance, look for the omega symbol, which looks like a horseshoe shape. And when checking continuity, look for the diode symbol, which looks like an arrow pointing to the right. Resistance indicates how easily current flows through a circuit, while continuity checks whether the circuit is closed or broken.

Most multimeters also measure direct current (look for the DCA designation), but not all models measure alternating current (ACA). There may be additional function settings, such as temperature measurement, DC gain, frequency, or special functions for testing common batteries by size.

Probe connection

Although readings are obtained from the multimeter, you can only test the power supply with compatible probes. You should see at least three probes connected, usually labeled "COM", "mA" and "10ADC".

COM stands for common and is the connector for the black probe. If you are measuring voltages or currents below 200 milliamps (mA), the red probe is connected to the mA port and if you are measuring voltages or currents above 200 mA, it is connected to the 10ADC port. If in doubt, use the 10ADC connector.

Using a multimeter

Before using the multimeter on an active or potentially active power supply, read the instruction manual for the specific model and pay special attention to the safety instructions. Not only is this the best way to become familiar with the multimeter's specific functions, but it is also an important check to minimize the risk of electrical shock. Using a multimeter with an improperly connected probe can also cause the multimeter to smoke, catch fire or even explode.

But once you are familiar with your multimeter and know how to use it safely, you can immediately use it for simple tests. Suppose you find a loose battery in a drawer and want to know if it still has stored energy. Just connect the probe to a multimeter and set the regulator to the highest DCV setting, since the battery uses DC power. Place the red probe on the positive terminal of the battery and the black probe on the negative terminal and you will see the voltage on the digital display.

Normal batteries such as AA, AAA, C and D have 1.5 volts when fully charged, while 9-volt batteries naturally have 9 volts. If the voltage displayed is lower than these values, you will know that part of the battery charge has been discharged.

You can also use a multimeter to check outlets that you think are not working properly. Set the multimeter to the highest AC voltage setting, hold both probes with one hand and insert the red probe into the smaller socket and the black probe into the larger one. If the sockets are working properly, you should see a voltage of 120 or slightly less. If you get a zero or a number below 110, you know something is wrong.

Exploring your home's electronics, batteries and electrical systems with a multimeter can be a fun way to learn the basics of electricity, as long as safety comes first.