Multimeter Basics: Read it Right, Stay Safe

 Welcome to Multimeter Basics. An electric multimeter is one of the most useful and helpful tools and resources you as a technician can use in the field. But not all multimeters are created equally. How do you use them safely? What is the function of each setting? And that's what we're going to discuss.

So there's basically three types of multimeters. You have an analog one. Which has a needle that will move back and forth. Typically, they're older, or you have the digital multimeter, and then you have two types of those. One that you have to settle the functions manually by buttons and switches, and one that does it automatically.

Most often. Technicians and maintenance, electrical, HVAC. We'll use some of the same few meters so you'll see them throughout the industry. In particular, a brand that I recommend is Fluke. Fluke is very well known. It's highly regarded in the industry, and everyone that I know is a technician that has one, really enjoys using it and considers it the best meter that they've ever had.

However, there are plenty of good ones, so find a brand that works for you. But I do recommend when you get a multimeter that you buy the best multimeter that you can possibly buy. For the applications that you're going to use, please don't buy the cheapest or least expensive multimeter that you can find, because quite literally, it can be the difference between you getting shocked or not.

And I want to make sure that you have a meter, you know how to use it, and you use the meter correctly because not all meters are as forgiving. Okay, so this one here is a fluke and you'll see 16 and the most common ones that you'll find, especially in the maintenance and. You know, HVAC will be a 16, a one 16 or a one 17.

And there are plenty of other models. The 16 is the one that I personally use. But again, find whatever you like. So you'll see that there's ranges of everything here. And so let's go over the buttons here. The first one is select, and you'll see, so when you turn the knob, the first setting that you see on the top, like here, it'll go from off to voltage, and then it's alternating voltage.

And then here we have Ohms, dde. That's what that symbol is. And then the speaker next to it is for continuity, which means it'll make a tone and we'll go through these together. And then below it you have micro amps, and then you'll see in blue is temperature. So on this meter you have select, we have range, we have the temperature function in Fahrenheit and Celsius.

And then of course you have the minimum and the maximum. So we'll go through each one of these settings. So the first one is voltage, and you'll see that it's alternating current or direct Current. Alternating current would be what's in most homes and direct. Current would be batteries. Nine volt batteries, aa, aa, D, E, c, batteries, car batteries, and some circuit boards.

So you have to know exactly. What you're working on in the system. The next setting, you'll see a few of them. The first one is on ohms, and then below that is DDE and continuity, and that will make a tone. And then below that you have Microamps. Multimeters measure a wide variety of measurements, but what they don't really measure is high amperage, which is why most technicians have a multimeter and an ammeter separately.

And then below that you'll see temperature in the blue, and that's operated by the function button at the top. So you have select which is which ones you want to go through the menu. Then you have the range, which in my experience is what most people. In the field don't set correctly. So I like to ask this question to most people.

When I teach this course, if you move the decimal on your paycheck, does it make a difference? And the answer is, yes, it does. It makes a tremendous difference depending on which direction it goes. So the same thing is true with the range. You wanna make sure that you have the symbols on here, and you'll see is it goes from mega ohms to ohms.

Tequila ohms to mega ohms, and it's very important that you know what range it's supposed to be in. After that. You can see on the top here in the select this temperature button, whether that's in Celsius or Fahrenheit. So on the bottom you'll have either multimeter leads or thermocouple, which you put, uh, we, we'll show you that, which you will use to measure the temperature.

Next, what you do when you, let's say you want to check continuity, you go right here and you'll see that it's under. You hit select until you see that symbol on the screen, and then when you touch the leads together, you'll have a tone, and that tone means continuity. Now, here's the deal. Some meters will have an auto range finder, so you have to really understand what meter you're buying, but continuity just means that there's a connection.

Just like if you were to put a piece of wire on between these two terminals, it would beep and make that noise. That does not measure the resistance. The same way it does on the Ohms setting. So now we went from Ohms here. Okay, so I'm gonna select it. That's capacitors Amper. So now we have Ohms, and I'm gonna hit the button until mega goes away.

Mega means million. So now if I put the leads together, I have 0.4, 0.5, 0.2 ohms. Each set of multimedia leads that you have. We will have their own amount of resistance in them. That doesn't mean they're bad. Very few of them are exactly zero, but they should be pretty close. So now when you measure the difference in Ohms, you can see that there's a variance between having the measurement on audio, on the tone.

For example, if I measure ohms in this setting, it's different and you will get a different reading almost always, unless it's an auto range finder. Then when it's just in ohms, now I put these together and you can see it's 0.3. Now if I put it on tone, you can see that it's zero. And so you'll find a difference.

So it's important to understand and we'll go over testing receptacles and some other components. So first and foremost, you have to know what type of meter you need, whether it's a. An analog one, which is typically much older, whether it's one that has manual functions or one that's auto everything. But the most useful one is that one that does as many functions that you need in the field that is safe.

If you have this meter in particular, if it's on the wrong setting, and I put this, I put voltage to these in a receptacle. The meter won't go bad. It doesn't blow a fuse, it just doesn't work. Some of them will make a noise to indicate to you. That you made a mistake and you should take a look at the settings, some of the meters, the Fluke one 17 is in particular will do this.

You put your meter near a voltage source and it will have a little light at the top that will illuminate and tell you that there's what it's called, non-contact voltage. So it's important that you know how to use this. We'll go over some of the practical tips. We'll go over an outlet, a switch, a three-way switch, a stove burner, and a capacitor.

So let's summarize everything. Okay. Buy the best meter that you can go with a known name brand that everybody knows and trusts, and just ask a technicians. And if you'd like, of course I'll have recommendations for you in particular. I like this one, know what all the functions are on the dial. So you'll see at the top.

All of these buttons here, and it's select range, temperature, minimum, and maximum. And then right below you'll have, of course it's off and then voltage, and you have to know if it's alternating current or direct current. In other words, from an outlet, receptacle, a transformer, or if it's from a battery basically.

And some circuit boards. Also, your terminals go in the bottom. The black one is your common right here. And the red one is your positive terminal, and then we move over here and you'll have ohms, and then you'll have a DDE with the tone for continuity. And then you'll have capacitors, and then you'll have microamps and below.

When you do temperature, you take these out. Put the thermalcouple in, and then anything that comes in contact with the thermalcouple, whether it's air or a surface temperature, such as your hands or something that's warm like a pipe, it will give you a temperature reading. So let's go do some tests.