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How to use a multimeter

No more scratching your head at malfunctioning appliances. With this guide, you’ll learn the ins and outs of troubleshooting your home and household electronics using one of your toolkit’s handiest instrument.

How to use a multimeter

Once reserved for engineers and electronic technicians, multimeters—sometimes called “multitesters”—have come down in price and size, making them indispensable for homeowners who have basic knowledge of circuitry. When troubleshooting problems with small appliances, smart-home modules, speaker systems, or just about any other electronic item, a multimeter will be among the most valued tools in your arsenal.

If you’re new to multimeters, these gadgets may seem daunting at first. Learn the basics, however, and you’ll soon be able to perform a number of diagnostic tests on your own. Because multimeters vary from model to model, be sure to study your specific unit’s operating manual before you get started.

How to use a multimeter

Two Types of Multimeters

Analog multimeters, or volt-ohm-milliammeters (VOM), have been around for decades and can still be found, affordably, at any do-it-yourself-type store. The new kids on the block—digital multimeters (DMM)—offer greater precision with decimal point readouts, even enhanced functions, such as the ability to auto-detect alternating current (AC) or direct current (DC).

Applications and Limitations

Both VOM and DMM models measure voltage, resistance, and current, replacing the need for individual voltmeters, ohmmeters, and ammeters. While you can test household voltage with a multimeter, electrical-current-testing is limited to low-voltage circuits, such as small direct current (DC) motors or low-voltage alternating current (AC) appliances—your thermostats and doorbells, for example. To avoid blowing a fuse, destroying the multimeter, or risking injury, do not attempt to test current higher than the maximum allowed for your unit.

Among other things, multimeters can determine:

  • Available battery charge
  • Voltage at an outlet or switch
  • Damage in cables and cords
  • Viability of fuses, diodes and resisters
  • Conductive ability of an electrical pathway

Measuring Voltage

With a multimeter, you can measure both AC and DC voltage—particularly useful for locating short circuits or determining if a rechargeable battery is holding a charge. Start by selecting the corresponding current on the multimeter and a voltage range higher than the current you’re testing. For example, if you’re measuring the voltage in a 120-volt wall outlet, turn the multimeter knob to the next highest option—200 ACV. If you’re testing a 12-volt car battery, select the next highest option—20 DCV.

Then make sure to connect your test leads to the proper jacks before testing: For voltage testing, plug the red lead in to the port labeled “V.” For this and all multimeter tests, the black lead plugs into the common (COM) port.

To test a battery’s DC charge, touch the red probe to its positive terminal and the black probe to its negative terminal; the multimeter will display the existing charge in the battery. Since polarity isn’t an issue in AC voltage, it doesn’t matter which probe you insert in either hole of a wall outlet; insert both probes, and the multimeter will display the voltage at the outlet.

Safety Tip: Hold probes by their insulated handles. Do not touch the metal part of the probes to avoid electrical shock.

How to use a multimeter

Testing Resistance and Continuity

In electronics, “resistance,” is the amount of hindrance to the flow of electricity, and less is more—or, rather, good for the operation of your appliances. Multimeter in hand, you can test resistance in circuit board components and appliance elements throughout the house. If, for example, a microwave isn’t operating as it should, this checkup could help you you determine if you should replace a single non-functioning component on the circuit board or buy a new microwave outright.

First, make sure the appliance is unplugged before testing. Plug the red lead into the port with the ohm’s symbol, “Ω,” and select the lowest ohms’ function on the dial. While you can test individual capacitors and components directly on a circuit board, you’ll get a more accurate reading if you remove a component and then test it. When you touch the black and red probes to both ends of a component, simultaneously, you’ll get a reading. The lower the reading, the less the resistance to electrical flow. By comparing the readings from other components on the circuit board, you can determine whether or not to replace a component with an unusually high reading.

To test the continuity, or continuous flow, of an electrical path between two points, plug the red lead into the “Ω” jack and turn the dial to the continuity symbol, “

”. A small reading—or a beep—indicates there is a continuous path between the two points. No reading or beep, however, indicates a problem. For example, if you’ve just put a new bulb in your lamp but it still doesn’t turn on, running this test at both ends of its power cord can confirm that an internally broken cord is to blame for your dim room.

Testing Low-voltage Current

In order to measure low-voltage current, the multimeter must become part of the circuit, allowing the current to actually run through the multimeter. This is handy for determining whether a low-voltage circuit, such as a looped set of solar-powered landscape lights, is getting power to all the lights. For this test, plug the red lead into the port labeled, “A,” for Amps, and select the next-highest Amps function on the dial.

Your operating manual may provide a chart, but if not, you can test a simple circuit by connecting the live feed from the power-supply (usually black) to the multimeter’s red probe. The multimeter’s black probe then connects to the positive wire (usually black) on the appliance you’re testing. Finally, the neutral power-supply lead (usually white) connects to negative appliance wire (also white). When you’ve hooked up the circuit correctly, turn on the power source to measure the electrical flow rate, or amps, through the circuit.

Safety Tip: As previously mentioned, do not test a circuit that exceeds your multimeter’s capability. Multimeters are “fused” at a maximum amount of voltage, which is typically lower than household current. If a multimeter bears the words, “10A MAX FUSED,” do not test any current you suspect might be higher than 10 Amps.

Created on: 9 August 2012

A multimeter is a measuring instrument that anyone involved in electronics will need to use at some stage. A multimeter can be used to measure voltage, current, resistance, continuity and other parameters.

Measuring DC Voltage and Resistance

The video below shows a multimeter being used to measure voltage from batteries (DC (direct current) voltage) and the resistance of some resistors.

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Measuring DC Voltage

Selecting the DC Voltage Range

To measure DC voltage using a multimeter, simply turn the selector dial on the multimeter to the DC voltage setting. On an auto-ranging multimeter such as the one shown in the video, there will only be one DC voltage selection on the dial.

A multimeter that is not auto-ranging will have a selection of voltages on the dial that can be chosen, e.g. 2V, 20V, 200V, 1000V. On this type of multimeter, start by selecting the highest voltage on the dial and then turn down to a lower voltage if the voltage measured is seen to be low. If you are measuring a single battery cell and you know that it is a 1.2V or 1.5V cell, then you can start by setting the multimeter dial to 2V or 20V.

Taking a Measurement

After selecting DC voltage on the multimeter dial, use the two probes to measure across the battery terminals. The black probe should be used on the negative terminal of the battery and must be connected to the COM connection on the multimeter. The red probe should be used on the positive terminal of the battery and connected to the connection on the multimeter that is marked V. This connection may have other symbols marking it as well, such as the ohm symbol (Ω).

After applying the probes to the battery, the voltage of the battery will be shown on the multimeter display.

Polarity

If the red and black multimeter probes are connected the wrong way around to the battery (i.e. black on positive and red on negative) then a digital multimeter will show a negative sign next to the voltage reading on the display.

On a digital multimeter, it does not matter if the leads are reversed when measuring voltage. Getting the leads the right way around (correct polarity – red on positive and black on negative) does matter on the old analog multimeters (the type with the indicator needle). An analog (or analogue) multimeter can be damaged if the polarity is reversed on the leads.

Measurement Results

In the video, batteries made up of 1.2V rechargeable cells are used. The first one measured has six cells, so the voltage should be about 1.2V × 6 = 7.2V. The second battery measured contains two cells or 1.2V × 2 = 2.4V. A single 1.2V cell is measured last.

When 1.2V batteries are fully charged, they will have a voltage of slightly more than 1.2V. This can be seen by the measurements taken in the video.

A multimeter is an electronics testing device that, um, tests multiple things, including resistance, voltage, and current. Using certain multimeter models, you can test to be sure that components — such as diodes, capacitors, and transistors — function properly. You can also troubleshoot your circuit to see where current is failing and pinpoint the problem spots.

You don’t have to break into your piggy bank to buy a multimeter. You can find them for about if you want fancy features, you can spend over $100. Find a model whose price you like and then splurge on the next higher-priced model. You will use a multimeter all the time. Trust us: It’s worth a few extra bucks for a better model.

How a multimeter works

A multimeter has a set of leads: a black one and a red one. You attach these leads to the component or portion of the circuit that you’re testing, and a digital readout provides the results. You adjust a knob to set the test you wish to perform such as resistance, voltage, or current as well as the range to test. Note: Some multimeters have an auto-ranging feature that saves you the trouble of setting the range.

Test leads that typically come with multimeters use simple cone-shaped tips. You can buy test clips that slip onto the cone-shaped tips to make it easier to clip them onto the leads of a component. This makes testing much easier, trust us.

The two things you’ll probably test most often with a multimeter are resistance and voltage.

Reading resistance

The problem with resistors is that manufacturers seem to expect you to memorize the color code that identifies the resistance rating. Here is an easier way:

1. Clip your test leads onto the resistor leads.

2. Dial your multimeter to the resistance range you think the resistor fits in.

3. Read the value.

If your multimeter reads 1, you guessed too low of a value. Move the dial to the next range up until you get a valid reading. If your multimeter reads at close to 0 (zero), you guessed too high of a value. Dial to the next range down until you get a valid reading; if you get to the lowest range and the value is still 0, whatever you’re testing has zero resistance.

Testing switches or relays is another common use of the resistance-testing feature of your multimeter. You can clip your test leads onto the lugs of an SPST switch to verify that it’s working. (Hint: Occasionally, they don’t work.) When the switch is open, you should get a value of 1, meaning that the resistance is higher than your meter can measure. When the switch is closed, you should get a low resistance — close to 0 (zero) ohms. You can also test SPDT or DPDT switches or relays to make sure which lugs are connected in which switch position.

Measuring voltage

To run a test to measure voltage, you connect the red multimeter lead to the positive side of the battery or circuit that you’re testing and the black lead to the negative or ground side and set the dial to the voltage range you expect.

Consider checking the voltage at the contacts of a battery pack. To do this, touch the red lead to one of the battery pack outputs and the black test lead to the other. With a 4-battery pack loaded with fresh batteries, you should get a reading of about 6 volts. (If you get a reading of -6 volts, don’t worry: Just reverse which lead you are touching to which battery pack output.) When batteries get old, the voltage drops. If you get less than 5 volts from a 4-battery pack, it’s time to get new batteries.

When a circuit doesn’t work, one of the first things to check is the voltage between the +V bus and the ground bus of the breadboard. Here’s how:

1. Strip both ends of a 3″ piece of 22 gauge wire.

2. Clip one end of each wire to one of your test leads.

3. Slip the free end of the wire attached to your red test lead into any contact on the +V bus.

4. Slip the free end of the wire attached to your black test lead into any contact on the ground bus.

Although you might not get a reading of the full 6 volts because of drain on the battery from the circuit, you should get a reading above 3.5 volts.

If you get a reading close to 0 (zero) volts, check to make sure that your battery pack and the wires from the battery pack terminal block are connected properly.

Introduction: How to Measure AC Voltage Using Multimeter

How to use a multimeter

How to use a multimeter

How to use a multimeter

Those who are beginners in electronics, this question often comes in their mind: ‘How should I use a multimeter?’

Well, we have something for you.

We have started video tutorial series on ‘How to use multimeter’ in our channel ‘Being Engineers’ and in this video, we will show you ‘How to safely measure AC voltages using multimeter’.

You will get an introductory video of this multimeter whose link is given in the description of this video.

Step 1: Take Precautions!

We have used Mastech MAS830L Digital Multimeter. If you don’t have it, please buy one from market near you or order it online from eBay or which ever site you prefer. I got this from market.

You must take the following precautions:

1. NEVER touch the probe tips

2. Always try to put the probe in correct position

3. Put the regulator in the correct position before taking any reading

Step 2: Put the Probe in Correct Position

First, set the multimeter in the range where V

is written and point it at 600

Step 3: Put the Common (black) Probe

Then you will have to put the common probe in the common terminal

Step 4: This Step Is Very Important!

Now, you must be careful in which terminal you are connecting red probe. Since you are measuring voltage, connect it to VΩmA. If you connect it to 10ADC, then say RIP to your appliance.

Step 5: Connect to AC Mains

Watch out for Ground and Live wire! Then connect black probe to one of the LIVE wire and red probe to the other LIVE wire! (Check the video)

We got a reading of 226V.

If you want to hold this reading, press hold button. (Marked as circle in the above image)

Step 6: Time for Removing the Probes

You have safely and successfully measured the AC voltage!

Now when you want to remove the probes, first remove the red one and then the black one.

So do it in the presence of an adult (or your teachers) if you are nervous, wear rubber shoes and gloves for extra safety.

If you don’t want to miss the upcoming tutorials, SUBSCRIBE to our channel.

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Introduction: How to Use a Multimeter Basics

How to use a multimeter

How to use a multimeter

How to use a multimeter

A multimeter or a multitester, also known as a VOM (volt-ohm-milliammeter), is an electronic measuring instrument that combines several measurement functions in one unit. A typical multimeter can measure voltage, current, and resistance. Analog multimeters use a microammeter with a moving pointer to display readings.

There are many types of multimeters for many applications but in this tutorial, we will take apart just the most common ones and not that expensive.

Step 1: How to Use a Digital Multimeter

A digital multimeter can be used for voltage, resistance, current, continuity, resistance, capacitance to test transistors,even the internal resistance of capacitor in /out the circuits.

Digital multimeters (DMM, DVOM) have a numeric display, and may
also show a graphical bar representing the measured value. Digital multimeters are now far more common due to their cost and precision, but analog multimeters are still preferable in some cases, for example when monitoring a rapidly varying value.

Step 2: Fluke Multimeter

Fluke Corporation, a subsidiary of Fortive, is a manufacturer of industrial testing equipment including electronic test equipment. It was started in 1948 by John Fluke, who was a friend and roommate of David Packard, future co-founder of Hewlett-Packard, when both were employed at General Electric.

These multimeters are the high end of multimeters well known as a precise multimeter and durable most professional electronic repair engineers use this type of multimeters

Step 3: How to Use a Multi Meter for Voltage

Voltage, electric potential difference, electric pressure or electric tension (formally denoted ∆V or ∆U, but more often simply as V or U, for instance in the context of Ohm’s or Kirchhoff’s circuit laws) is the difference in electric potential between two points.

In the past, for reding just voltage we will use a voltmeter, but more practical this days is to use a multimeter because is got multiple functions and you don’t need a device for each application.

Step 4: Volmeter Ammeter

You have to remember that measuring voltage is very easy and all of the new multimeters have build in the auto function to detect the voltage or if not they have the option to choose from AC/DC.

AC voltage (alternating current) is the voltage and current in our mains plug 120/110/220/240v and the property of this type of voltage/current is fluctuating back-forward 50/60 Hz times/second the main advantage of this type of voltage is the very long distribution range in comparison with DC.

DC voltage is a straight type of voltage/current and is associated with batteries 12v/9v/1.5v

Step 5: Test Battery With Multimeter

The multimeter has this special function where it can detect the voltage and you have the option to choose the range for your appropriate voltage reading and if somehow you will exceed that voltage on the multimeter lcd screen will appear the symbol 1 meaning the voltage is above the range selected

Step 6: Continuity Check

In electronics, a continuity test is the checking of an electric circuit to see if current flows (that it is in fact a complete circuit).
A continuity test is performed by placing a small voltage (wired in series with an LED or noise-producing component such as a piezoelectric speaker) across the chosen path. If electron flow is inhibited by broken conductors, damaged components, or excessive resistance, the circuit is “open”.

Step 7: Multimeter Symbols

You have here a picture of a multimeter symbols

Essentially, a multimeter is an electronic tool that measures current,
voltage, and resistance. (You may also have heard them referred to as “multitesters.”)Current is measured in amps, resistance is measured in ohms, and voltage is measured in volts. There are two main types of multimeters: analog meters and digital meters. Though analog meters use a needle to render measurements, today most people use digital multimeters. Digital multimeters are usually more accurate and offer more consistent readings.

Step 8: Inside a Digital Multimeter

Here you go a quick pick to see inside a digital multimeter its not complicated but not easy as well these device help

electronic hobbyist to perform the most basics forms of testing voltage,current,continuity,resistance and after you master all these procedures than you can buy a professional multitester and spend more but till then you can play with a cheap and reliable one

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To measure the current running through your LED circuit, you must pass the current through your multimeter. The only way to do this is to interrupt the circuit between two components and insert your multimeter, as if it’s a circuit component, to complete the circuit.

Switch the multimeter selector to measure DC current in milliamps (mA). Then break the connection between the resistor and LED. (If you are using alligator clips, simply remove the clip that connects the resistor and the LED. If you are using a breadboard, remove the jumper wire.) The LED should turn off.

Next, touch the positive (red) multimeter lead to the unconnected resistor lead and the negative (black) multimeter lead to the unconnected LED lead, as shown. The LED should turn on, because the multimeter has completed the circuit, allowing current to run through it. The current reading shown is 2.14 mA.

How to use a multimeter

Now, insert your multimeter at another connection point in the circuit (for instance, between the positive battery lead and the resistor), taking care to open the circuit at the point of measurement and to orient the multimeter leads with the positive lead at a more positive voltage point than the negative lead. Do you get the same current reading as before? You should, because this simple circuit provides only one path for current to flow.

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With so many battery operated products in the house, multimeters have become the need of this day.

Today, we are here to tell you how to use one correctly. From TV and AC remotes to battery operated lights, there are a lot of products that need proper functioning cells to run. Even our cars cannot run without cells.

With multimeters available on the internet and in shops, it is easier to buy one and take care of all your batteries at home itself. As such, you would not need to visit a mechanic at a garage.

But if you are confused about buying a multimeter because you do not know how to use it, here’s a guide that will provide the details. Read on to learn how to measure voltage levels for different types of cells. Also, we will tell you how to understand when to buy new batteries because they are running out of juice.

Let’s turn on the ignition and proceed!

How to Check Battery Voltage Using a Multi-meter

How to use a multimeter

Firstly take a multimeter and place it on the table. Also, bring in the battery you want to test. We will explain the process with a 9-volt battery for this guide. To correctly measure the voltage, turn your switch dial to DC voltage measurement.

This needs to be done because a battery generates DC power, and this means you will need to measure it with the same unit. So it is essential to know the maximum voltage of the battery. Set the dial to 20 volts, which is the maximum range.

Connect the test probes to your cell, with the black wire meeting the negative. The red wire should meet the positive and then check its display. If you get a number which is higher than 7 for a 9-volt battery, it is still usable, and the cell will last for some more time.

On the other hand, if it is a dead battery, it would show results below 1. If that is the case, it is time to buy a new one. Mostly, it is enough to just check the voltage to get a clear understanding of the battery.

But if you have to ensure that it can supply sufficient current to a load, you would need to measure the amperage in milliampere-hour (mAh). We will discuss this in the next part.

How to Measure Battery Amps with A Multimeter

So here we will talk about how to get accurate measurements of the current of a battery. The average amperage of the battery would be somewhere around 100 mAh. So before measuring, turn the dial to DC function and keep it at 200 mAh.

Again connect your test probes in a similar way where the black wire meets the negative. The red one should connect to the positive. After you are done, check the reading on the display.

If it fluctuates somewhere around 100 mAh, it is working alright and will run any small device efficiently. We tested it on our TV remote control battery, and we got 98.3 on our display, which was a satisfactory result.

While testing your battery, if you find the number to be below half the voltage level of any cell, it is time to replace it. This is because once a battery reaches its midpoint, it starts to drain away quickly.

If you do not have a digital multimeter, you can also try using a simple voltmeter or an analog multimeter. These do not come with a digital display but will let you take accurate measurements with a facility to read it from the scale directly.

A digital variant is easier to use and will always be the preferred choice, but again, it is not the only way to get the job done. There are a number of multimeters available in the market today that simulate a load to test the battery. These devices can be great additions to your tool collection.

How to Use A Multimeter To Test A Car Battery

If your car battery is causing problems or you have an issue with dim headlights or delayed ignition, a multimeter can come to the rescue. This product can also be used to check the health of heavy-duty car batteries or alternators.

Though you can already see the battery level on your dashboard display, it may so happen that the battery has completely drained out. In such a case, you would have to open the bonnet to get access to the battery, and that’s when you need a multimeter.

The process is the same as above. You would need to connect the probes to the battery terminals. Then proceed to check the reading on the multimeter display.

The battery ratings vary a lot from car to car, but choosing 15-20 Volt is good enough. We selected 20V before proceeding to measure the level. Allow us to give you a piece of advice here – you should keep the headlights on for a few minutes before checking the battery. This would drain away any remaining charge.

If your measurement is more than the minimum value, which is usually 12 volts, the battery has a good charge and will last. However, this is not the only way to judge if the battery is in perfect condition. One also needs to check if the car is able to draw power successfully.

A quick way to come to a conclusion is to test the cold cranking amps (CCA) that trigger the ignition. Most car batteries tend to function well for 3-4 years before deteriorating.

How To Test The Cold Cranking Amps (CCA) of a Car Battery

To test the cold cranking Amps, keep your multimeter connected to the battery terminals and then fire up the ignition of your car. This is a job for two people, where one needs to take control of the ignition while the other checks for fluctuations while the engine is cranked up.

The ideal situation would be if the reading drops to 10V but then returns to a higher value around 12 V. If the reading stays constant after the initial value drop, then you would know your battery is in perfect condition. The engine needs to be running throughout the process.

If the initial reading is around 5V and not below it, you should know that the battery is slowly dying and would not work for long. Also, if the reading is way below 5V, then it is time to replace the cell.

Make sure that you do not try to do it all by yourself. Take another person’s help because if you try to handle both the engine as well as the measurement, you may end up with an incorrect reading.

How to use a multimeter

Conclusion

Now you know how to go about using a multimeter to test batteries. It is fairly easy once you are well-versed with the process.

However, we strongly recommend that you practice on different cells to get the hang of it. Maybe consider practicing with the different batteries used for household items like the remote, video game, torch, and even a battery from a lamp. The more you play around with different cells, the better you understand various charge positions.

We hope this guide was helpful in explaining to you how to test a battery with a multimeter. If you still face any problems, do let us know in the comments section below.

You can use your multimeter to measure the voltage across the battery pack, the resistor, and the LED in a circuit. Note that the connection points between components are the same whether you built the circuit using a breadboard or alligator clips.

The red lead of your multimeter should be at a higher voltage than the black lead, so take care to orient the probes as described. Set your multimeter to measure DC voltage and get ready to take some measurements!

First, measure the voltage supplied to the circuit by the battery pack. Connect the positive (red) multimeter lead to the point where the positive (red lead) side of the battery pack connects to the resistor, and the negative (black) multimeter lead to the point where the negative (black lead) side of the battery pack connects to the LED. See the following figure. Do you get a voltage reading that is close to the nominal supply voltage of 6 V? (Fresh batteries may supply more than 6 V; old batteries usually supply less than 6 V.)

How to use a multimeter

Next, measure the voltage across the resistor. Connect the positive (red) multimeter lead to the point where the resistor connects with the positive side of the battery pack, and the negative (black) multimeter lead to the other side of the resistor. See the following figure. Your voltage reading should be close to the one that appears on the multimeter in the figure.

How to use a multimeter

Finally, measure the voltage across the LED. Place the red multimeter lead to the point where the LED connects with the resistor, and the black multimeter lead to the point where the LED connects to the negative side of the battery pack. See the following figure. Was your voltage reading close to the one in the figure?

How to use a multimeter

The measurements show that in this circuit, the battery pack is supplying 6.4 volts, and that 4.7 volts are dropped across the resistor and 1.7 volts are dropped across the LED. It’s not a coincidence that the sum of the voltage drops across the resistor and the LED is equal to the voltage supplied by the battery pack:

A give-and-take relationship is going on in this circuit: Voltage is the push the battery gives to get current moving, and energy from that push is absorbed when current moves through the resistor and the LED. As current flows through the resistor and the LED, voltage drops across each of those components. The resistor and the LED are using up energy supplied by the force (voltage) that pushes the current through them.

You can rearrange the preceding voltage equation to show that the resistor and the LED are dropping voltage as they use up the energy supplied by the battery:

When you drop voltage across a resistor, an LED, or another component, the voltage is more positive at the point where the current enters the component than it is at the point where the current exits the component. Voltage is a relative measurement because it’s the force that results from a difference in charge from one point to another.

The voltage supplied by a battery represents the difference in charge from the positive terminal to the negative terminal, and that difference in charge has the potential to move current through a circuit; the circuit, in turn, absorbs the energy generated by that force as the current flows, which drops the voltage. No wonder voltage is sometimes called voltage drop, potential difference, or potential drop.

The important thing to note here is that as you travel around a DC circuit, you gain voltage going from the negative terminal of the battery to the positive terminal (that’s known as a voltage rise), and you lose, or drop, voltage as you continue in the same direction across circuit components. (See the following figure.) By the time you get back to the negative terminal of the battery, all the battery voltage has been dropped and you’re back to 0 volts.

How to use a multimeter

With all circuits (whether AC or DC), if you start at any point in the circuit, and add the voltage rises and drops going around the circuit, you get zero volts. In other words, the net sum of the voltage rises and drops in voltage around a circuit is zero. (This rule is known as Kirchhoffs Voltage Law. Kirchhoff is pronounced “keer-cough.”)

Keep in mind that these voltage drops have a physical meaning. The electrical energy supplied by the battery is absorbed by the resistor and the LED. The battery will keep supplying electrical energy, and the resistor and LED will keep absorbing that energy, until the battery dies (runs out of energy). That happens when all the chemicals inside the battery have been consumed in the chemical reactions that produced the positive and negative charges. In effect, all the chemical energy supplied by the battery has been converted into electrical energy — and absorbed by the circuit.

One of the fundamental laws of physics is that energy cannot be created or destroyed; it can only change form. You witness this law in action with the simple battery-driven LED circuit: Chemical energy is converted to electrical energy, which is converted to heat and light energy, which — well, you get the idea.

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How to use a multimeter

Running a test on wires using a multimeter is very easy, so long as you have the appropriate skills and knowledge. The main reason for testing wires is to examine continuity between the two ends of your wire. However, this is only possible when you make use of a multimeter, as this helps you in doing a continuity test.

Therefore, when testing for continuity in your wires, stick two terminals of the multimeter against the two ends of electrical energy. Running this test is very vital in case you are to either repair or install an electrical device or component in an appliance, fuse, car, or outlet since poor continuity might cause significant damage through fires or shocks to your entire electrical devices.

  • What to do?
  • Here are the steps you need to follow.
  • Conclusion

What to do?

Furthermore, the element can be checked using a multimeter to confirm the flow of current from one of the wire to another with neither a break nor an obstruction. Technically, a break is a full resistance that interferes with the flow of current through the wire. Therefore, it is always advisable you switch off the breaker on the signal that you are running the test on to avoid any possible severe damages.

Here are the steps you need to follow.

  1. Make sure you disconnect the wires that you are planning to test for your safety, as well as to prevent any damage to the electrical equipment.
  2. Connect the red and black terminals of your multimeter to the corresponding slots, with the front of the multimeter having several holes for the terminals. Subsequently, plug the red cord in the slot with a label for measuring amperage, voltage, ohms to measure current and the black cord in a slot labeled (COM), which stands for common, and this is the ground. Additionally, it would be best if you ignored the port with the 10A labeling, as this is used to measure maximum current. You must note that the red probe stands for active current while the black terminal is the ground, especially if you are examining voltage, and there is no difference amongst the cords. The visible metals at the end of the red, as well as the black cord, are referred to as terminals; they are meant for measuring electrical currents.
  3. Switch on the dial on your multimeter for continuity setting, and this is usually located at the bottom right side of the dial. However, the sign for continuity differs depending on your model and brand, though the continuity mode has a diode sign that is triangular with an alignment on its right side. Furthermore, it also has a symbol similar to a sound wave. However, if you are not sure about it, you should confirm from your manual to get the proper details and information. Moreover, if your multimeter lacks a continuity setting, you can still do a continuity test on the wires by turning the dial down to the minimal number of resistance mode. You should take note that resistance is measured in ohms.
  4. Touch the metal parts of your multimeter’s terminal together to make sure it works. This is for confirmation, and for continuity, settings touch your two terminals together continuously holding them in position. If the reading displayed on your multimeter is under 1, this means your multimeter is functioning accordingly. Likewise, even if the reading displayed is 0, this is still okay since when the signal is good, the multimeter will typically produce a beeping sound. This is usually an assurance that the continuity setting is functioning accordingly.

In most cases, if there is no beeping, you will probably get a maximum reading value, which will require you to go back to your settings and examine the dial for assurance purposes that you are in the right settings. Moreover, you will also have to confirm the ports in which your terminals are plugged. Lastly, you are required to replace your terminals before referring to your manual script on how to reset your multimeter.

  • When testing for an electrical signal, ensure you turn off and then unplug the device you want to test. This is because it might be dangerous to run a continuity test as active electrical signals flow through the wires, outlet, or even sour of power. Thus, you should ensure there is absolutely no flow of current during the entire process of testing. Nevertheless, it would help if you took note that some electrical devices such as radios, car systems, and hot tubs usually store charge even after you switch the power off. Therefore, you need to wait for at least 1 hour before you start conducting the test. Subsequently, place the black terminal on the first end of the wire and confirm that the metal piece at the end of your terminal maintains constant contact with the wire being tested. Afterward, place the red terminal on a different part of the wire, and this will probably connect the two terminals using a wire. The current would then be spontaneously transmitted to the other terminal hence displaying a reading.
  • Wait for the number to stabilize and then examine the reading being displayed to get your resistance. Usually, the number displayed on your multimeter is not always stable, so you should wait for about 3-4 seconds while maintaining the two terminals in position to get an accurate reading.
  • You need to understand the readings being displayed on your multimeter, and it may either correct or incorrect, depending on your multimeter settings. If it displays a reading of 0, then continuity is excellent. However, the reading below 1 indicates an excellent continuity but not perfect continuity, and this could be a sign that the dirty, but it is still safe to use such a wire. However, if the number is greater than 0, this means your battery is faulty and most likely going to die. Additionally, if the reading is higher than 10 ohms, you then should know you have a poor continuity, with this meaning that the resistance is higher than expected, and the wire needs to be replaced. Therefore, you are not supposed to use the wire unless it is fixed properly.
  • Conclusion

    Having read through this comprehensive article, you now know how to make use of a multimeter to test a wire. Therefore, you are better-placed to know whether or not a wire is damaged beyond repair and needs replacement, with this important to ensure the proper running of your electrical equipment.