Hey everyone, I thought about writing a lengthy blog post on how to use multimeters for beginners. However, once I started writing I realized that this could have turned out to be the longest post in history! So, I decided to some searching on YouTube, and came across probably the best video I have seen on how to use multimeters for beginners. A lot of great tips on everything from voltage measurement, to resistance measurement, to measuring current. Basically everything that you will need to know once you have purchased your new multimeter.
I’ve decided I’m going to upgrade some of my tools and purchase a new multimeter. This hasn’t been an easy decision, I’ve had my trusty Fluke meter for years and it has never skipped a beat. I will more than likely buy a fluke multimeter again, there’s a reason they are considered by so many electricians to be the best in the business. The reason I’ve decided to upgrade is because I want to give my nephew a multimeter, and try to get him interested in electronics – just like I was introduced when I was a child.
I’m not just going to jump into it and buy a multimeter straight away, I’m going to do some thorough research to see what the best multimeter is these days. I know there’s been quite a few great meters come out in the past decade, but also some not-quite-so-great ones too. My top requirement is that it has to be durable. In my line of work, as a maintenance electrician, things can get a little rough sometimes with heavy machinery, grease and weighty tools nearby. I’d be devastated if I’d just bought a new meter, and accidentally crushed it in the bottom of my tool bag once I’d put some heavy tools on it. A cheaper, non-durable meter would be fine if I was working with small electronics on a table and in a safe environment, but that just isn’t the case. Along those lines, it would also be absolutely necessary to come with a protective case – or be able to purchase one along with it.
Next on my list would be that it has to come with the ability to be able measure high currents. I will look into whether or not I will get one with a built in clamp meter or not. When you’re dealing with machinery that runs on hundreds of amps, you need to be able to test those amps quickly, safely and accurately.
I will want a multimeter with a good, extended warranty – the minimum would be 3 years. I feel that if your meter has lasted for three years with every day use, then you have got your moneys worth. But like I said, three years is the minimum, if I can find one with a 5 year or even lifetime warranty, then that will rank very highly on my list.
I’m assuming the cost of the multimeter I buy is going to be above $400, I do not mind paying so much because the way I see it, even if it lasts me for 3 years then it only works out to a couple of dollars per week. And you always pay for quality. So to recap, my top 3 requirements for the meter I’m going to purchase are:
Must be durable and be able to withstand being used in a large factory for years to come.
It has to be able to measure large currents – whether with a built in clamp meter or with an attachment.
It must come with at least 3 years warranty, but a lifetime warranty would be the best.
I will be reading a few guides and reviews in the coming days before I buy my multimeter.
Today I’m going to show you exactly how to test a transistor with a multimeter to see if they are good or faulty. You can do this with ANY multimeter, yes that’s right. All you need is to be able to select the Ohms setting. This method will only work with PNP of NPN transistors, it will not work with FET transistors.
Plug your leads into your meter, black lead into the common jack and red lead into the Ohms/volts jack.
Set your multimeter to the Ohms on the dial and then if you have the ability to select range on your meter, select a very high range – in the meg-ohms.
Place your transistor on a flat surface in front of you, facing up. From left to right, the pin outs will be Emitter, Base, Collector.
Next, place your black probe on the emitter, and red probe on the base. If you get a reading on your meter, the transistor is good and it’s an NPN transistor.
If you place the black probe on the base and red probe on the emitter, and you get a reading then it’s an PNP.
If you get a reading both ways, then the transistor is likely to be shorted and is faulty.
If you get a reading on your multimeter when testing between the emitter and collector, then your transistor is also likely to be bad.
It’s that simple! Transistor can be quite fidly to test, due to being such a small component, but once you’ve tested them a few times, you’ll be doing it like a pro. As always, if you have any questions or comments about this article, feel free to send them through and I’ll be happy to get back to you.
I came across this video by Khan Academy the other day. It’s one of the best explanations of voltmeters and ammeters that I’ve ever seen. The creator explains in simple, easy to understand terms how and why voltmeters and ammeters are connected the way they are.
Some key points from the video:
Current is measured with an ammeter, voltage is measured with a voltmeter.
Voltmeters are always connected in parallel, because you want to measure the voltage between two points.
Ammeters are always connected in series, this is because you want measure the current going THROUGH the circuit. If you connect the ammeter in parallel you are very likely to damage it.
Ammeters are made with a very low resistance so that they do not disturb the amount of current that is flowing through the circuit.
Voltmeters are made with a very high resistance, so that a high current does not flow through them when testing between two points.
A circle with the letter V inside it is the symbol for voltmeters in a circuit.
Resistors are identified by the letter R followed by a number.
I hope you take away some useful information from this video, once you get the concepts everything seems to fall into place a lot easier. If you have any queries, feel free to shoot me a message.
I thought I’d put up a post about things that I see in my day to day life as a maintenance electrician, I hope you enjoy it.
Today was a pretty crazy day at work. It started out with me being called to investigate some heater elements in an oven at the end of a conveyor line. There were 4 elements out in a row, so this told me it was not just something wrong with the individual elements, it was more likely a circuit breaker had tripped or a fuse had blown. After checking the control cabinet, my suspicions were confirmed – a circuit breaker was tripped. But this wasn’t the end, I had to find the cause of the breaker tripping. I grabbed my multimeter, found the terminal of the elements and set my meter to ‘continuity’. I tested the neutral wire to ground and just as I suspected, my meter beeped – indicating that there was a short circuit from neutral to ground. That was the easy part – the hard part now was finding where on the cable it was touching to ground. After about 30 minutes of carefully searching along the elements cable, I found the spot where the cable insulation had worn away and had touched the metal frame of the oven. A bit of new insulation done the trick, the circuit breaker was reset and the oven started up with all elements working!
On to the next job, I was required to change over a faulty fluoro light in the office. I had to wait until everyone went to lunch so I could shut the power off to the lighting circuit (people don’t like to work in the dark!), this was a quick simple change over. After completing the job, I wanted to see what was actually wrong with the light to make it fail. Using my multimeter, I tested along the various components of the light, first the wiring circuit, which tested okay, then the capacitor which seemed fine, next was the ballast – it tested faulty. I decided it was cheaper and easier to replace the whole lighting unit, rather than order and replace the ballast. That’s the thing with electronics – it usually works out cheaper to replace the whole unit, rather than replacing individual components
The biggest and most stressful job of the day was when the main conveyor line suddenly shut down for no reason – this is stressful and puts me under the pump, because for every minute this is stopped, it is costing the company hundreds, if not thousands of dollars. My first thought was to check all the individual emergency stops on the line – sometimes people can accidentally bump these, causing things to shut down. Once all those were checked and looked to be fine, I went to the main control board and could see that the line still had to power to it. I next checked all the circuit breakers, which were okay and then checked out the motor overloads – I could see one had been tripped! I pulled out the electrical drawings and found the motor overload in the drawings, and looked to see which motor was corresponding to that overload. Upon inspecting the motor, I could feel that it wasn’t turning freely, this can normally mean two things, it is either seized or that something outside the motor is jamming it. Considering the motor looked quite new, I decided to focus my fault finding on the latter. After a few minutes of inspecting, I could see that the chain on the conveyor had been jammed by a stray bolt! I wasn’t glad that the conveyor had shut down, but I am glad that it was such a easy fix! My pointy nose pliers grabbed the bolt out with ease, the overload reset and the line was back in business.
Overall the line was down for about 30 minutes, not great, but it could have been a lot worse if the motor was actually seized.
Days like today make me proud to be a maintenance electrician, it’s very rewarding once you’ve repaired a piece of machinery and got it back up and running when there’s people depending on you.
Are you searching for topics related to how to test your car battery with a multimeter? If you are then you have come to the right place. At some point you may have tried to start your car only for the engine to fail to start, or maybe you realize the lights were flickering. Such problems may be caused by a faulty or flat/drained battery, and unless you know how to use a multimeter, you may end up wasting lots of time, effort as well as money finding the fault. So, how do you test the car battery?
1.Turn off the Engine
Fist begin by turning-off or shutting down the engine and letting it cool down. This allows the voltage as well as gases inside the battery to stabilize.
2.Disconnect the Battery’s Positive Terminal
When you look at the battery, you will notice two terminals connected to the car. One will be red in color and will be marked with a (+). This is the positive terminal. The other terminal known as the negative will feature a black cover and is marked (-). Disconnect the car wire connected to the positive/red terminal.
3. Select the Correct Setting
Most multimeters feature three jacks. NE will link to a red probe, the other to the black probe, while the other jack/hole will be indicated com. Select the Voltage(V) setting on the multimeter and make sure the red wire/probe is inserted into the red jack and black lead into the black jack. I always wipe and clean the battery to get a good contact.
4. Measure the Voltage
Connect the red lead from the multimeter to the battery’s positive and black lead to the batteries negative terminal. A good battery should read between 12.4 and 12.7 volts. Anything lower means the battery needs recharging while a value higher than 12.9volts signifies an overcharged battery.
The above are the simple steps to testing the battery. I can’t overemphasize the importance of safe working. Always, switch off the engine and disconnect the positive battery terminal first. Don’t work in a poorly ventilated environment or near flammable gases or materials. Also, use a high quality multimeter that meets the market standards. I believe the above article has certainly answered your question on ‘how to test your car battery with a multimeter’. There you have it, if you have any more questions on how to test a car battery with your multimeter – please contact me via the contact page.
Welcome to my blog, MultimeterPro. I’m really excited about launching this blog, multimeters have been somewhat of a passion of mine since my dad gave me his second hand one when I was about 15 years old. You would continually find me running around our house (my to the dismay of my mother), pulling electronic appliances apart to test all the components inside – then putting them back together again. This allowed me to gain a great deal of knowledge, not only in how the meters worked and performed, but how everyday electrical appliances worked too. This knowledge expanded over the years and allowed me to gain employment in a job I love, as a maintenance electrician. As you can guess, I’m pretty happy to be using these great tools every day in my job!
Over the years, I bought various testers from ammeters, analog ohmmeters, digital ohmmeters, voltmeters, current clamp meters. But you’ll mainly find me blogging about digital multimeters on here.
In the MultimeterPro blog, I’m going to share with you as much information as I can about getting the most out of your tools and using them in the safest possible manner. Some of the things I’m looking forward to sharing are:
The history of the digital meter and how they evolved from radio receivers invented in the 1920s, to what they are today.
Explaining what terms like capacitance, decibels, frequency, inductance, conductance actually mean – and do you actually need to measure all of those with your multimeter?
How to best take care of your electronic tools, to keep them in top shape and performing as they should for years to come – a must for safety!
Various opinions and anecdotes from my everyday life working as a maintenance electrician – you would not believe some of the dangerous electrical issues I encounter on a day to day basis.
I invite all of my readers to comment, share and get involved with all of my posts – I’d really love to hear from other people who are as interested in multimeters as me. Please, if you have any questions, please do not hesitate to get in contact with me – I’m more than happy to answer!
Thank you for visiting and reading, I’m thrilled to have you here and look forward to communicating with you!