small battery How to use a multimeter to test batteries, phone jacks, cables and more

The other day, I stopped at the hardware store and picked up a door stopper that you installed on the hinge to prevent the door handle from hitting the wall.We had it all over the house, but there was one that was Brass and my wife wanted it to be white so I was there, looking for what I'm trying to describe by waving my hands and incoherent in the air.Continue laughing, of course.I now know it's called the "hinge pin door station" but I didn't know it at the time so I had to wave.
Anyway, when I did, a woman walked into the store and looked very anxious and distracted, and I told the clerk to help her when I tried to find what I wanted.Before I started doing this, she blurted out a tragic story about some electrical equipment and the seemingly very critical need to figure out why it didn't work.Her husband asked her to go out and buy a "continuity tester ".
The clerk shook his head sadly, saying that he did not think they had such a thing.I had to step in."Of course you need it," I said, "she needs a multimeter ".So we went to the place of the multi-meter, and sure enough, they had a few models.
I explained that the meter was a great thing when testing everything at home and helped her pick a basic model.I showed her how to find the "Ohm" setting for the continuity test and she left happily.The clerk also understood what I wanted and took me to them.
I picked the white one my wife wanted and I was on my way home too.I see a wide variety of articles online that tell you how to test the power outlet using a voltmeter.They usually remind you how dangerous the electricity is, and remind you where to put which voltmeter probe, and are very sure not to touch bare metal and so on.
Why are you doing this?If you need to test the power outlet, plug the light into it!Of course, if you are a convenient person with a basic understanding of home appliances, maybe you will poke the watch in the wall switch from time to time, but most homeowners will not do so, they probably shouldn't do that either: I 've seen "convenience" because they're not careful about the electricity at home, so they 've smashed their ass.They are "lucky"People are messed up by things they don't have business.However, something in your home is low voltage: phone jack, doorbell, thermostat line.
You can get a little sting from something like this, and if you're really unlucky, you can also damage things, but, it's unlikely that you'll be on the evening news because of this.Better yet, many appliances can be tested with power off, and killing yourself becomes more difficult when there is no power connection.Although this is not impossible.A classic example is the old CRT tube used by TV and computer monitors.
Even if the power is unplugged, these puppies can store a lot of voltage..Your average homeowner should not do this.You can buy a very good home multimeter for ten dollars.
If you hang out near Amazon, you'll find them on that level, but you'll also find them higher --Even a few hundred dollars higher.Those that are more expensive are either better quality or have special features to test specific things.You need these tools.Probably not to test things around the house.
Oh, they did do something around the house test.Here is a phone jack tester.This won't do anything you can't do with a standard cheap multimeter, but you have to learn or already know some telephone lines that use the meter.Professional tools like this allow you not to have to learn these things.
This is another kind of special tester.
These are for RS232 ports-The old serial port.Almost no one has these anymore because they have been replaced by USBOf course, you can also find testers for this.Again, most or all of these things can be done with a multimeter.
You may need some basic knowledge about how something you are testing should work, but finding this on the internet is usually not difficult.You can also test a lot of things without knowing any details.You need to understand the basic functions of the meter and some circuits.
I'm going to talk a little bit about it here with your meter, and almost certainly it comes with a brochure that tells you how to use it.The internet is in trouble again.From the most basic to very advanced skills.We live in such a wonderful time, don't we?Sometimes the hardest part of the test is to connect things so you can test it.
Like I said, crocodile clips are helpful.
Soon after we moved into our new home, we had a phone jack problem.Short and wrong combinationBut most of my tools and stuff are still packed and what I really need --Crocodile clipDidn't show up when I needed it.I improvise with these Molly bolts.The screws at the top gave me a place to fix the wires I needed to test, and the small slots gave me a place to plug the meter test probes so I didn't have to fix them well.
Rube Goldberg?Sure.
But I got it done, right?Your meter can basically test three things: A/C voltage, DC voltage, and continuity.When you're buying a home meter, here are three things to look.It may not say anything about continuity.This is the confusion of the clerk in my hardware store.
He knows that the meter tested some mysterious things called "Ohm", but he doesn't know that means they can test continuity.Ohm actually measures resistance, which is useful from time to measure, but very low resistance means you have good continuity (at least for the kind of thing you might play at home ).Your meter will be equipped with a cable or probe.
Good with crocodile clips-These are convenient for cutting to the wires to be tested.Let's talk about those test cables, shall we?One of the places where manufacturers can save money is there.These cables have thick metal ends, but the insulated wires connecting these ends are very thin.
If you cut one, you might be surprised how thin it isEspecially if there is a very cheap meter.Cheap test probes like this tend to break with use.You won't know it's broken, so this is the first thing we learn how to test: is the meter cable OK?Insert the red cable into the red jack on the meter and insert the black cable into the Black Jack.
If they don't have color, put black in the "" or "front" Jack and red in the "-\ "Or \" negative \".Honestly, it's okay if you get it wrong.You will not hurt the meter if you are testing continuity.However, some instructions for testing more complex things will tell you to put red or black in a specific place, and while it may not matter if you put them behind, it may, so develop the right habit.
If you look closely at the picture on the right, you will find a crocodile clip on my meter.That's because the original probe that came with it was cheap and broke down about a year after I bought this.I temporarily found some spikes that are perfect for the meter and they asked me to use these clips that I already have.
The "black" is actually green, but the electricity doesn't care what color the insulation is, so it's good for me.If you notice that the dial of the meter is turned to the RX1K position, there is a small symbol next to it that may remind you of a pair of headphones.This is the Ohm symbol, and this is where we want the meter to be set to measure the resistance.
If you touch the other end of the meter probe together now, the meter dial should move to the right.The digital meter will change from showing an infinite resistor (or maybe just "1" or "0L") to a zero resistor.If it doesn't move, you either have a bad meter probe or forget to put the battery in the meter.
A battery?Yes, a battery.
The meter requires a battery to measure continuity.Another thing about cheap electricity meters: batteries may not be easy to buy.I need a very small screwdriver to open my case.
It does use the standard AA battery, which is a good saving.If the meter does move but does not move to the right all the time (or if the digital meter does not indicate something 0 ohm or very close), the battery of the meter may be old and weak.Good news: you can test the battery and you may not even need any battery in the meter to test the battery.
To test the AA battery, set the meter to DC v.If it has multiple options, please select the lowest-It's 15 volts on my meter (it just says "15" on the dial ").Touch the red probe at the bottom of the battery-the flat end.
Touch the Black probe at the top-Small raised end.Your meter should move or show how many Volts the battery can produce.If it is much smaller than 1.2 volts, insufficient battery power.If you have an old analog meter like me then it's hard to read the scale accuratelyCompare it to another new battery to see how weak it is.
The thing about testing the battery is this: except for 9 volts, it's easy to test the battery with a crocodile clip, and testing the battery is a clumsy task.It is not easy to fix the probe in the appropriate position, especially with small batteries.This is a great place for a dedicated battery tester.
There's another way to test a nine volt battery-Touch it with your tongue.A new 9 v battery will make you bite sharp, while a weak battery will make you feel almost no sting.The more wet your tongue is, the less you bite.
I don't recommend doing this often, but it's quick for an emergency where you strongly suspect the battery is dead.One of the more common things you might test around the house is the lights.Of course, this is usually a bulb, but you can test the light switch if you know you have a good bulb.
Here you can see that my meter is connected to the lamp head and set up for the continuity test.Turning on the switch should cause the meter reading.What if not?If not, either the switch is not good or you have a loose disconnection somewhere.
Let's assume you have confidence in changing the switch.It's not difficult to do this.This may require a little finger power and some basic tools, but you can find good instructions, even videos, on the Internet.If you're going to do this, you 'd better test it while you're doing the wires.
You can even do this before you completely remove the lights.If you can find the wire, remove one from the switch (as shown below when you unplug the light and connect it to the meter), you can touch the loose wire to the other wire, the meter should show 0 ohm or good continuity.If not, the wires will break somewhere.Another fairly simple thing to test is the phone jack.
Again, you can easily find Internet articles to show you how to isolate whether the problem is inside or outside the house, but there is a very simple thing in the old house, you don't even need 1 m.It's corrosion.Just shine a flashlight into the Jack and you can see it if your eyes are good.I had a very old Jack in our first home and after living there for 20 years we started having weird phone issues.
When I peek at a Jack, it kills every phone at home as long as there's anything plugged in, and I can actually see the green crud on the wire.After that discovery, I replaced every Jack in the House;They all have at least some signs of corrosion.You also want to see DC voltage in that Jack.
There can be AC "ring" voltage, but it is more difficult to test.So how will you install these thick probes on these tiny wires?You don't need to do that.If you remove the jack from the wall, the wires are neatly separated and exposed for you.
I added another set of wires in this photo so I can extend to a more convenient place --The Jack was buried behind a small closet.Adding these other wires made me not have to squat in the dark corner to work and I couldn't see the meter without a flashlight.As for what to look for, place the "\" probe on the green wire of the Jack and then touch the other one to red-You should see about 48 v dc.
If you don't see anything, try it another way --Maybe it's wrong.Plug in the probe either wired or backward.For more details, but if you can't find the voltage anywhere, it means that the Jack is not connected to the phone company (or the phone company is down now ).
It is often easy to test the continuity of any kind of computer cable.The only hard part may be the metal part.Given how cheap these things are usually, I will almost automatically change another cableI might just test the bad cable out of curiosity if it works, but really, what's the point?Why bother you to throw it away?If the problem is not continuous, you will be looking for the voltage and for that you need to know what to look for and where.Of course, the internet is your resource.As you can see, a cheap voltmeter can be a useful tool and it is not difficult to understand its basic use.
I hope this article will help you understand this