How to Read a Multimeter?

It’s a common misconception that all electricians need to be able to read an electrical meter. Fortunately, this is not the case. 

If you’re starting as an electrician aspirant or if you’re interested in getting into the trade, then you might want to know how to read a multimeter before reading on.

The first thing you’ll notice about a multimeter is that it has two probes sticking out of it, and either one can be used for testing voltage, amperage, or resistance. 

Both probes must be there because some measurements require more than one probe; they also need a power connection using at least two wires. The three main types of readings are voltage (V), current (I).

Multimeter Basics

A multimeter, like a ruler for distance, a stopwatch for time, or a scale for weight, is a useful tool for measuring electricity.

In contrast to these other instruments, however, it may also be used to measure a variety of quantities; in this regard, it is similar to having a number of separate measuring instruments in one convenient package. The majority of these devices have a front-mounted dial that can be adjusted to accommodate a variety of measurement types, such as current, voltage, and resistance.

Multimeter Features

Keep in mind that the continuity check feature on your multimeter can help you determine if two objects are electrically connected.

Connect the test probes to the ends of your device under test, then power it on. Your meter will sound an alarm if a full circuit has been established between its probes; otherwise, it will remain silent.

The multimeter’s usefulness is not limited to simply measuring current and voltage. In addition, some of them measure efficiency by checking components like diodes, capacitors, and transistors. You should check the owner’s manual before attempting to use any of the functions you are unfamiliar with.

Multimeter Setting

To begin using your multimeter, you must first familiarize yourself with its many settings and acronyms. First, choose if you’ll be working with volts (V), amps (A), or ohms (Ω). Choose the V setting if your current is alternating; select the A setting if it is direct. When the indicator becomes green in front of the appropriate reading scale, the dial has reached the correct position for measuring resistance (.001-100kohm range max).

As long as every section is green, you can proceed with the measurement without worrying about which one goes with which.

Put a little more on the scale than you think the voltage should be in order to get a more precise reading. If your multimeter can be set to 20 volts, for instance, that is the value you should use for this test.

How to Measure With a Multimeter

Nearly all multimeters have the ability to measure current, voltage, and resistance. For your convenience, we’ve provided definitions of the following terminology below. If you need help learning how to use a multimeter.

It is helpful when constructing circuits or soldering wires into place to have a device that can verify for electrical continuity by beeping loudly if two things are electrically connected.

You can use it to ensure that nothing is wrongly connected, which could result in a short circuit and subsequent damage.

Assembling circuits requires an understanding of diodes and their applications. Like a one-way valve, a diode only lets current flow in one direction.

If you’re not sure which direction your component should be inserted into a circuit or if it’s functioning properly, a multimeter with this functionality can help you out. In such case, before you put this feature to use, make sure you’re familiar with all it’s capable of doing by consulting the owner’s manual.

If you’re in the market for a multimeter, it’s important to know which functions are must-haves. Consider upgrading to a more sophisticated model if you need it to perform a variety of tasks, such as determining the value of a capacitor or transistor.

Amps, Volts, and Ohms

Understanding certain fundamentals of electricity is necessary prior to playing around with a multimeter.

  • These voltaic pushes are measured in amps, so if more current is rushing past a given obstacle (as it would be during a lightning strike, for example) than usual, that obstacle will have a higher amp rating.
  • Electrical voltage, or the “push” exerted on electrons as they move across a circuit, is measured in volts. Using the familiar metaphor of water moving downstream, and supposing that voltage represents the pressure driving the river, we can understand what is happening.
  • Resistance in a circuit can be measured in ohms, and a higher value implies that less energy is being sent through that section of the circuit.

A Multimeter for Voltage Measuring

Here is how to use a multimeter to determine the voltage.

  1. The voltage you find using a voltmeter at home is presumably alternating current. Measuring a car battery or other device that operates on direct current (DC) is indicative of DC.
  2. Please check that the selection switch is set to the correct voltage. The symbol for alternating current is a sine wave, while the DC symbol is just a solid line with a dashed line underneath it.
  3. Make a connection between the multimeter’s black probe and its COM port.
  4. Don’t forget to connect the red probe to the V-shaped jack.
  5. Ensure that you are working at full power by setting your voltage selector to its highest level. Remember that mV stands for thousandths of a volt, and select the lowest setting here.
  6. Safety gloves should be worn at all times when testing alternating current to prevent electrocution.
  7. Start your car or flip a breaker to power on the item you’re testing.
  8. When taking a reading, insert the black probe into one of the component’s terminals and the red probe into the other.
  9. If the reading is unclear, try the next highest setting on the selector until you reach the maximum that can be recorded.

Analyzing AC Voltage Measurement

The voltage is usually lower than it should be. The good news is that this can be easily measured using a multimeter. Since not every plug or connector is compatible with every other, you just need two probes and some extra time to find the right connections in your gadget.

It is reasonable to anticipate a -10% to +5% variation in any given alternating current power supply. Even at a single point of connection, there is still some room for error in voltage readings, but as long as the average is within the acceptable range, everything should continue to operate normally.

Conclusion

The ability to read an electrical meter is not a requirement for becoming an electrician. Voltage (V), current (I), and resistance (R) are the three most common measurements (R). Both of the probes on a multimeter can be used to measure voltage, current, or resistance. A Guide to Using a Multimeter. Virtually every multimeter has three separate measuring functions: current, voltage, and resistance.

If you need it for multiple purposes, you might want to invest in a more high-end version. Before messing around with a multimeter, it’s important to have a firm grasp on the fundamentals of electricity. At home, a voltmeter should reveal alternating current when measuring voltage. A direct current (DC) measurement would be made using a car battery or another DC-powered device. There is still some margin for error in voltage readings, even at a single point of connection.

Content Summary

  • It’s a common misconception that all electricians need to be able to read an electrical meter.
  • If you’re starting as an electrician aspirant or if you’re interested in getting into the trade, then you might want to know how to read a multimeter before reading on.
  • The first thing you’ll notice about a multimeter is that it has two probes sticking out of it, and either one can be used for testing voltage, amperage, or resistance.
  • Connect the test probes to the ends of your device under test, then power it on.
  • You should check the owner’s manual before attempting to use any of the functions you are unfamiliar with.
  • To begin using your multimeter, you must first familiarize yourself with its many settings and acronyms.
  • Put a little more on the scale than you think the voltage should be in order to get a more precise reading.
  • If your multimeter can be set to 20 volts, for instance, that is the value you should use for this test.
  • Nearly all multimeters have the ability to measure current, voltage, and resistance.
  • If you need help learning how to use a multimeter.
  • If you’re in the market for a multimeter, it’s important to know which functions are must-haves.
  • The voltage you find using a voltmeter at home is presumably alternating current.
  • Measuring a car battery or other device that operates on direct current (DC) is indicative of DC.
  • Please check that the selection switch is set to the correct voltage.
  • Make a connection between the multimeter’s black probe and its COM port.
  • Ensure that you are working at full power by setting your voltage selector to its highest level.
  • Safety gloves should be worn at all times when testing alternating current to prevent electrocution.
  • Start your car or flip a breaker to power on the item you’re testing.
  • The voltage is usually lower than it should be.
  • The good news is that this can be easily measured using a multimeter.
  • It is reasonable to anticipate a -10% to +5% variation in any given alternating current power supply.

About Blake Sutton

Blake has worked as an electrician for over 10 years, receiving his Journeyman Electrician license in 1998. Looking to take his professional electrical career further, in 2008 he received his Bachelor of Science in Electrical Engineering (BSEE) from the University of Texas in Austin. Blake now works full time as an electrical engineer, specializing in power systems.