First, there was the galvanometer, then came the voltmeter, and today, scientists, electricians, and anyone else working with electricity use a multimeter, also known as a DMM (for digital multimeter).

The multimeter is basically a digital version of an AVOmeter, which was designed in the early 1920s by British Post Office engineer Donald Macadie to measure amps, volts, and ohms (hence “avo”). There are still plenty of analog volt-ohm-milliammeters (VOMs) around, but DMMs are more common and have more functionality.

The applications of multimeters are varied and not confined to the measurement of voltage, current, and resistance. You can use a multimeter to test for continuity in a circuit and, depending on the model, to measure capacitance. With most models, you can also test batteries, diodes, and transistors and distinguish between DC and AC current.

Getting to Know Your Multimeter

In terms of usability, accuracy, and functionality, there’s a big difference between an analog and digital multimeter. An analog VOM relies on electromagnetic induction to move a needle, but a DMM has internal circuitry that is more sensitive to minute impulses, and reading an LED display with decimal fractions is more reliable than gauging the position of a needle between meter graduations.

Every multimeter can measure volts, amps, and ohms, and most have a dial that allows you to adjust the sensitivity. On a reasonably priced meter, you’ll find DC voltage settings from 200 millivolts to 1,000 volts and AC voltage settings from 200 millivolts to 750 volts.

The meter also detects both AC and DC current from 2 milliamps to 20 amps and measures resistance from 200 ohms to 200 megohms. If the meter measures capacitance, it does so on scales that extend from 2 nanofarads (10-9 farads) to 200 microfarads (10-6 farads). Some meters adjust the sensitivity internally. All you have to do is set the dial on the quantity you’re measuring and the meter does the rest.

Most DMMs have a setting for testing diodes, designated by the diode symbol. Some also have a setting for testing transistors, labeled hFE. Your meter may also have a setting for testing batteries, but you don’t really need this. You can test any battery by using the DC voltage setting in the range of the battery’s charge.

How to Use a Multimeter

Every multimeter comes with a pair of probes, one black and one red, and three or four ports. One of the ports is labeled COM for common, and that’s where the black probe goes. Two of the other ports are labeled A for amps and mA/µA for milliamps/microamps. The fourth port, if there is one, is labeled VΩ for volts and ohms. The fourth port is sometimes incorporated into the third one, which is then labeled mAVΩ.

If the meter has four ports, plug the red probe into the VΩ port to measure voltage and resistance, plug it into the mA port to measure current in milliamps, and into the A port to measure current in amps. To test a diode, use the VΩ port. You can also use this port to test a transistor, or if the meter has a multi-pin input port, you can plug the transistor into that.

To make a measurement, set the dial to the quantity you’re measuring and choose the appropriate scale. If the scale is too large, you’ll get an approximate reading, and if the scale is too small, the reading will be off the scale. Either way, no harm will come to the meter. Touch the probes to the terminals of the device or circuit you’re testing and read the measurement from the LED display or the analog scale.

The Main Applications of a Multimeter

Any scientist who works with electrical equipment needs a multimeter, but so do tradespeople, such as electricians and appliance repair professionals. A multimeter is also something that should be in every home tool chest because it’s an invaluable tool for diagnosing problems with household circuitry and home appliances.

Every multimeter can measure voltage, current, and resistance. These functions are necessary for diagnosing circuit problems and detecting worn-out components.

Testing voltage: Use the voltage setting to measure the voltage drop across circuit components and to measure the total voltage across a circuit. You’ll need the DC voltage setting for most small circuit components and for testing batteries and the AC voltage setting for testing residential circuit components, such as light switches, light fixtures, and outlets. Note that you can measure voltage without disconnecting the circuit. Simply touch one probe to the negative terminal or, if testing AC voltage, to the hot terminal. Touch the other probe to the other terminal and record the reading.

Testing current: You normally use the mA scale for testing current through electronic circuits and the A scale for testing residential current. To test the current, the meter must be part of the circuit. In most cases, you have to take a break in the circuit, and then connect one wire to one of the meter probes and the other wire to the other probe.

Testing resistance: The meter has a built-in power source that is activated when you choose the resistance scale. It sends a small current from one probe, and the smaller the current recorded by the other probe, the higher the resistance. If the second probe records no current, the meter displays infinite resistance or the letters OL, which means open line. This function is useful for continuity testing. You can also use it to check a diode by checking the resistance in one direction across the device, then reversing the probes and checking resistance in the other direction. If the diode is good, you should get low resistance in one direction and near-infinite resistance in the other.

Uses of Multimeters

The uses of multimeters are many, even if you aren’t a professional tradesperson or a lab worker. It comes in handy when you want to do any of the following things:

Test batteries: Just use the DC voltage setting and touch the probes to the battery terminals to determine how much of its original voltage the battery supplies.

Determine if a power cable is broken: Measure the resistance between the hot and neutral wires of any residential electric cable. If the resistance is infinite, or the meter reads OL, the cable is damaged.

Test a switch: If a light fixture isn’t working, or is flickering, testing the switch is often the first and easiest step to diagnosing the problem. To check a switch, choose the 200-volt range, place a probe on the terminal connected to the load and place the other probe on the ground screw. You should get a voltage reading of around 120 volts when the switch is closed and o volts when it’s open.

Test an outlet: To check a household outlet, choose the 200-volt range and insert the probes into the outlet slots. If you don’t get a reading of around 120 volts, there’s a problem with the outlet or the circuitry.

Test old incandescent light bulbs: Adjust the meter dial to test for resistance or continuity. Touch one probe to the screw thread and the other to the foot on the bottom of the bulb. The bulb is bad if the display shows OL or the meter shows infinite resistance.

source:https://sciencing.com/test-multimeters-7464091.html

further: How to Use a Multimeter

Like any other product, 3D pens come in many variations. It sometimes feels confusing to settle on a particular one. Thinking of the different brands, different filament types, different sizes, different operating temperatures, different speeds, different thicknesses, the mind can really go wild.

To save you all the trouble, I suggest following the recommendations of experts who have already used the 3D pens and know their pros and cons. Reviews Rabbit put together quite a comprehensive buying guide for 3D pens.

    

What is the best 3D pen to buy?

A list will perfectly fit this question – and that depends on what you are using the 3D pen for. They say that one man’s meat is another man’s poison. 

• If you are an architect, go for the 3D Simo Kit
• If you like multitasking, purchase the 3D Simo Multi Pro
• If you are a kid, consider using the 3D Simo Basic 2
• If you travel widely, the Lix pen is your go-to 3D pen
• If you are a professional designer, go for the MYNT3D Pro printing pen
• If you are looking to get started with 3D art without draining your pockets, think of the Dikale 07A
• If you are a professional with a good foundation in 3D artistry, the 3Doodler Create+ best suits you.
• If you are a creative adult with a desire to explore everything 3D, I recommend the AIO printing pen
• If you are an absolute beginner, the CoLiDo 3D pen will start you off well
• If art is your source of livelihood, order the Scribbler Duo asap.     

Are 3D pens worth it?

Yes, they are more than worth it. When I first developed the urge to get into 3D printing, I read quite a lot of reviews on the best 3D printers in the market. My conclusion was that I needed more than 600 USD to obtain a reliable 3D printer. And that comes with added logistics of space and the like. Comparing that with the less than 100 USD needed for a high end 3D pen, it made me think twice. And on top of that, the 3D pen literally brings out the creativity in you – unlike the 3D printer which does much of the work for you. That is the reason I find 3D pens worth it. 

Are 3D pens safe?

There are two major safety concerns regarding the use of 3D pens. The first one is the possibility of burning your fingers through touching the heated nozzle. The risk is especially higher with small kids whose heartbeat is simply exploring the unknown.

Another safety concern is the emission of fumes, especially with the ABS filaments. Experts have however rated these fumes as simply unpleasant, but not toxic. The filament can only produce toxic fumes when heated above a certain temperature range, which is not achievable with 3D pens. 

How long do 3D pens last?

Look at your 3D pen as you would any other electronic device. The better you handle it, the longer it will last. One common problem with 3D pens is clogging of the nozzle. As such, pressing the advance button no longer drives the filament forward as should be. Good news is that this is a repairable defect. 

To enhance the durability of your 3D pen, always allow it to cool down after using it continuously for about 20 minutes.

Going camping away from home on holidays is a current travel trend. To have a comfortable camping trip and dispel the stress in life and work with your car, you need to have a careful preparation.

1. Check and maintain the vehicle

Before starting a long tour, take your car for a thorough inspection and fix the dangers that could damage your vehicle and have problems in the journey.

Ensure the normal performance of the car on difficult roads, carefully check safety equipment.

In addition, if you often go far with your car, equip yourself with some knowledge of self-repairing, fixing some simple problems to be proactive in bad situations. Along with that, the driver should prepare some necessary items such as the tire of the car in good condition, the glasses, the flashlight, the jack, the electric pump, and the basic car repair kit.

And to be more sure, you should actively find the phone numbers of the mobile vehicle repair service centers near the areas you pass by as a backup.

2. Prepare essential items

The essential items you need to prepare such as:
– Tent
– Food and drink
– Medical supplies
– Basic car repair kits

For a tent, if you use an SUV car, refer to an SUV tent. If traveling with a large number of people, choose a family tent with large size.

In addition, you should equip yourself with a map of the area where you are camping, because there are not always phone waves (especially mountainous areas), so in many cases, you may lose your way. when the map on the phone cannot be supported because the wilderness has not been updated or there is no signal available to use the Internet.

3. Go camping in groups

Traveling alone or just one car is not a good idea as anything can happen on the road. Traveling in groups of people and vehicles will help you get more timely and safe support on difficult journeys. Of course, it is an exception if you want privacy or are the type of person who likes to be “alone”.

In this case you are the type who likes to “stand-alone” on the journey of discovering and experiencing nature. It is advisable to notify relatives and friends of the place you plan to go to in case something might happen that prevents you from returning home as planned.

4. Limit parking in the wilderness

You should not drive a vehicle moving too long in the remote forest road area if you do not really know the terrain of that area. Especially in the afternoon, it will get dark very quickly, with no street lights, no houses, no convenient services, but you still cannot find a way out. Not to mention the case of your car having unexpected problems without the skills and experience to handle it.

In particular, do not stop your car in areas too far from residential areas, isolated while you go with few people and not familiar with the terrain there.

5. Master some driving techniques

Are you learning about darts to entertain and compete with friends during your home days?

Want to drag your kids or yourself off the TV screen or smartphone for a few hours with a game like a dart?

Or are you preparing for a professional darts tournament?

So with the above requirements, you are wondering where to start?

Let this article help you.

Most of us start playing darts primarily for entertainment purposes, or for those who are passionate about the sport, they choose to participate in professional tournaments to challenge their abilities.

For each different purpose, in addition to learning how to play or dart board, the most important thing is to choose darts.

There are two types of darts, including steel tip darts and soft tip darts.

Steel tip darts have a point made of metal and are designed to play on bristle dart board. Soft tip darts are made from plastic, commonly used on plastic boards or electronic dart boards.

To choose from a beginner, you should first base on what you need to do. Then there are the physical properties and advantages of each. Let’s take a closer look at the differences.

See more: Best Darts For Beginners

1.Steel tip darts:

Steel tip darts are also known as traditional arrows. In other words, right from the beginning when the dart game was born, people used steel darts. That’s why in professional tournaments or long-time players choose steel darts because of its tradition.

Heavier steel tip darts should generally be more beneficial than soft tips in the probability of bouncing off the board. The common weight of steel tip is from 20-30grams, which helps them to allow heavier throwing and greater accuracy. The sharp and strong steelhead can pierce through most dart boards easily. The rate of steel tip being ejected is very low.

The steel itself is an alloy of iron and carbon, thus giving the darts a boost and lower fabrication costs. Hard steel heads rarely break and rarely bend unless they intentionally throw or hit the hard surface. So the durability of the steel tip is also higher than the soft tip.

However, this type also has some disadvantages. During throwing, if you miss the dart, chances are you’ll damage the wall and leave traces like scratches or holes. Besides, this type of steel darts is not recommended if your home has young children or children play this type. Sharp and sharp steel heads will endanger children.

For professional players or those who are interested or want to have more experience with this game, we recommend using steel darts.

2.Soft tip darts:

Soft darts are a relatively new type of dart recently accepted and popular in the dart playing community.

The soft tip darts are made of nylon or plastic. Sometimes they come with magnets, depending on whether the board is electronic or magnetic. Soft darts are most often used on electronic dart boards.

This type of dart is ideal for indoor play. They are completely harmless to children. Soft tip darts also won’t damage, scratch the walls, or even damage other objects like steel tip darts. This is also the recommended type of darts to play in crowded parties or groups of beginners to avoid minimizing the risk of an accident.

Soft tip darts are often used when the player owns the electronic dart board. The electronic dart board is a relatively popular board type nowadays because they integrate many different games and can automatically calculate points.

The downside is that soft darts are more likely to be worn when played regularly. Because it is made of plastic, it is more fragile than steel. You will need to replace them more often. When buying a soft-headed dart, you should buy the spare so it is always available when you need it.

Soft tip darts are made of plastic so are lighter in weight, which affects the way they are thrown at the board. So soft darts should only be used with an electronic darts board, use with ordinary dart board easily makes darts bouncing and not sticking to the board.

If you’re used to hardening steel noses, this can take you time to figure out how to throw better.

3. What type of dart should I use?

3.1: Do you want to try both types of darts?

Nothing is impossible. But please consider and research carefully before playing both at the same time, with different characteristics as we have analyzed above, this will affect your accuracy.

Steel darts will be heavier than soft darts, so the throwing force for these two types also needs to be different. Also, the standing distance when throwing is different and the dart board for these two types has a different distance structure.

3.2: If only you want to choose 1 of 2 options

We recommend that you choose according to the intended use.

If you just want to play darts to entertain friends or play at parties or play at home, to avoid accidents or unintended incidents and to be safe for children and pets, soft darts tip is the wisest choice.

For long-time players or professional players who participate in tournaments, steel tip darts will be preferred. Steel tip darts will help you practice better for professional tournaments. Because according to the rules of most tournaments about darts, even just in local bars, only steel tip darts are allowed.

Practicing with steel darts will give you an advantage when competing against other players. You can also play a competitive game with your friends. This will give you the feeling of a real expert.

However, you should stay away from areas where there are children or animals and should prepare yourself wall protection.

Conclude

Hopefully, the above analysis has helped you to come up with clear ideas. First, enjoy it as interesting entertainment, then if interested, try more to challenge yourself. As long as you feel happy and comfortable playing it is okay!

You may also like: 

• How To Play Darts
• Best Electronic Dart Boards 2020

five easy tricks for longboarding

today we’re going over five easy tricks for you to do on your longboard

we’re starting now

what’s going on guys

a few months ago I have a post about five easy longboard tricks for the beginner and you guys seem to really like that

so, today I have five more easy beginner flip tricks for you guys to do on your longboard

so you have a longboard and naturally, just because of the shape of this board you’re not going to be doing the same tricks and you normally do on a skateboard but there are a few fun easy flip tricks you can do

the first easy flip trick

I’m going to show you is the boneless finger flip

to do this trick you’re going to need to know how to do a boneless obviously

and I actually made a trick tip for that trick right here

somewhere you can click on that one in the middle of your boneless

what you’re going to want to do is use a hand that grabs the board and use it to rotate the board to get it to flip before landing on it

it’s important that when you’re trying out this trick you want to get the flip-down perfectly

you don’t want to over flip

if you don’t want to under flip you got to get it down just right

the next trick is the no comply finger flip

this is pretty similar to the boneless finger flip but instead of doing a full grab

when popping up the board you’re going to pop the board up on its own and then you’re going to flip it

you can either grab the board from the nose and flip it with your front hand or you can just kind of smack the board in the middle to make it flip

just make sure to get it as smooth as possible

I don’t want to see you guys taking multiple sets doing this trick

it’s just one set once that for the no comply that’s it

seemore:

• best longboard for heavy riders – top 8 model 
• best longboard for kids

next trick is the ghost ride kickflip

this is probably the easiest of the tricks

all you’re really going to be doing is quickly stepping off the board and then using your back foot to flip the boards before jumping back on it

make sure to go at it with full commitment and practice doing the trick on grass or carpet to get to flip down

this is really easy it’s a really fun trick and it’s definitely tricky that you should be trying out right now

this next trick is probably the hardest of all of the beginner flip tricks today

this is the old-school kickflip

if you want to check it out it’s going to be here

I should probably learn where these cards are going to pop up but whatever pops up that’s where you got to click to watch for this trick

you’re essentially hooking your back foot under neath the board and then jumping up

because of where your foot is when you jump up the board’s going to do a flip

I’ve seen people do these with a 180 body varial but when I do them I prefer to land back to regular do

whatever is more comfortable for you just remember that foot positioning is crucial when it comes to this straight

related:

• best longboard for cruising
• best longboard for pumping

next trick is probably the hardest trick of all time

it’s called the pick of your board and does

whatever you want flip literally just pick up your board throw it, around spin it, around slap it, do whatever you want and just flip it have fun with it

I like to learn tricks on both my skateboard and longboard but to me,

I just get to have fun as corny as it is to say remember is that having fun on your board is what it’s all about

source: eskatevsboard.com