How to Measure Current
To measure current with a digital multimeter it is possible to follow a few simple steps: Turn the meter on Insert the probes into the correct connections - in many meters there are a number of different connections for the Set main selector switch on the meter switch to the correct measurement. Sep 25, · Current Measurement using Multimeter Both AC and DC currents can be measured with a multimeter by connecting the meter in series with the circuit, in which current being measured provided the current in that circuit is limited or controlled by a load or appropriate values of resistance.
Circuot Membership. Study uding electrical engineering articles and papers in Low- and High-Voltage areas. Digital multimeter has generally replaced the analog-type multimeter as the test device of choice for maintainers because they are easier to read, are often more compact and have greater accuracy. Digital multimeter performs all standard analog-meter measurement functions of AC and DC.
Some offer frequency and temperature measurement. Figure 1 illustrates a typical autoranging digital multimeter. Usijg course for the meter to be of any use it must first be connected to the circuit or device to be tested. Both leads, one red and the other blackmust be inserted into the correct meter lead jacks.
The black lead is connected to the meter jack marked COM or common. It is usually the lower right jack as in this illustration. Be aware that not every meter has the same jack configuration. The red lead is connected to either of the appropriate jacks depending on what the maintainer wants to measure — ohms, volts or amperes. The two jacks on the left are utilized when measuring current, either in the mA or the 10 ampere range. Figure 2 shows the steps that should be followed when hoq resistance.
If a resistor does open, the digital multimeter display will flash on and off or display OL open line because the resistor has an infinite resistance. Figure 3 shows the steps uding should be followed when measuring voltage.
The measurement of both voltage and resistance is where how to survive 2 cheats digital multimeter finds its greatest utilization. If you reverse the connections, a digital multimeter with auto-polarity will merely display a minus sign indicating negative polarity. With an analog meter you risk damaging the meter. Kultimeter 4 shows the steps that should be followed when measuring current.
The measurement of current ib rarely performed when troubleshooting, as the circuit path has to be opened to insert the digital multimeter in jow with the current flow. However, if current is to be measured, the red lead is inserted into one of the ampere jacks, 10 amp 10A or milliamp mA input cirvuit depending on the expected value of the reading. I want to know why Star Delta Transformer is used for long high voltage transmission in electrical power system.
An exercise for the readers: What circuitt wrong with the lead photo with the automotive battery. Why does it appear to show the correct although negative voltage. Search for:. More Information ». Basic measuring of resistance, voltage and current using digital multimeter. Few words about digital multimeter Digital multimeter has generally replaced the analog-type multimeter as the test device of choice for maintainers because they are easier to read, are often more compact and have greater accuracy.
Many have such features as peak-hold display that provides short-term memory for capturing the peak value of transient signals how to tie down luggage on a roof rack well as audible furrent visual indications for continuity testing and level detection.
Do not be misled if your meter reading is slightly different from the color band on the resistor. A resistor will rarely short, but typically will open. Related EEP's content with sponsored links. It helps you to shape up your technical skills in your everyday life as an electrical engineer. Professional in AutoCAD programming. Leave a Comment Cancel Reply.
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Different ways of measuring currents
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). Feb 09, · Steps for Measuring Current with a Multimeter #1Turn off the power in the circuit that you are working on. It is a safety precaution that helps to avoid the risk of electric shock as you are setting up and preparing your equipment. Wear insulated work gloves as an additional safety measure. Jul 05, · Step 1:Connect the testing leads to the multimeter. Step 2: Turn the knob to the DV voltage segment in the multimeter at 40DCV. Step 3:Connect the probes in the circuit according to the polarity. Fig. 4: Image of multimeter showing DC voltage Step 4: Power on the Multimeter. Step 5: .
Just like stethoscope for doctors, stack overflow for programmers, spanners for Mechanic and Jarvis for Tony Stark a Multimeter is a very essential instrument for engineers who are interested in working with electronics. Perhaps this would be the first instrument that we get introduced to when starting to explore things related to electronics. In this article we will learn how to use a digital multimeter and how this will help us in our journey with electronics, this will be a very basic article which will take your through the different operations of a multimeter will illustrative pictures and videos.
At the end of this article you will learn how to measure voltage with multimeter, measure DC current, check for continuity, measure resistance and also check if few components like LED and diodes are in working state. But trust me they will be very useful when you are trying out stuff on your own.
Hence sit back and read through, while I will try making this article as intresting as possible. There are two different Voltages in general that can be measured by the Multimeter.
Let us start with DC voltage. There are two things to check on a multimeter before proceeding with any measurement. They are the Position of Test Leads a. By default the position of black test lead should be in the COM slot and the Red test lead should be in the V slot. This position will change only if we are measuring current. So, to measure a voltage the black test lead should be in COM slot and red lead should be in V slot.
Now we have to select the Mode by using the regulator like knob in the centre of the multimeter. We should look for the DC voltage symbol shown in picture below and select a range under it. Based on the voltage level that you are planning to measure you can select the range. For example if you are measuring 35V and if you place it at 20V range then you meter will read simply read 1, this means that you should select a high voltage range in this case V.
Once we have set the meter we can simply place the probes on the terminals on which we have to measure the voltage. Place the red lead on the positive terminal and Black Lead on the Negative terminal and you will get the value of Voltage. If you reverse the polarity of the cable you will still get the value but it will be with a negative sign, always use the probes in correct polarity to avoid errors.
You can measure voltage of a battery, DC adapter, Phone charger and even the voltage drop across each component in a circuit while debugging applications.
The below video shows you how to measure DC voltage with Multimeter. While AC voltage is rarely measured using Digital Multimeter it is still important at places where AC mains are involved.
Now set the mode by using the knob, we have to place it at AC voltage symbol shown in picture below. Normally we will have two ranges for AC voltages, they are V and V. For measuring AC voltage in India which is V we have to place it in V mode as shown in the picture below. The measuring process is exactly similar to measuring DC voltage, but here we do not have any polarity since we are dealing with AC. The following video shows how to measure AC mains voltage using a Multimeter.
Most of the conventional Multimeters will not have the option to measure AC current, hence we will discuss only about measuring DC current, however if you are looking for a instrument to measure current Clamp meter. Do not try measuring AC current with your DC multimeter it might damage the meter permanently. To measure DC current the black Probe should be placed in COM slot and the red probe should be placed in the A slot as shown in the picture below.
This is done because current should always be measured in series. Also note that some meters might have two A slot based on the range so make sure to read the symbol before connecting. Then we can select the mode by turning the knob to the dc current symbol shown in picture.
Again we have ranges from micro amps to 10A we can select the required range. In the below image the meter is set to read DC current at 2mA. So I am using the same V slot. But if the current is 10A then I should have changed the slot. As said earlier, current can be measure only in series with the load.
So if you want to measure the current drawn flowing through any wire, you have to disconnect the wire and place this meter in series by placing one probe at one end and the other at the other end. The below video shows how to measure the current flowing through a wire that is powering the LED. Another important and useful feature of a multimeter is checking for continuity.
This is a life saver tool that helps to debug electronics, be it your new PCB or a simple breadboard connection you can use continuity tool to check if there a connection between two terminals. This can also be used to detect broken wire. The check for continuity of any wire or circuit , place the Black probe on the COM slot and the Red probe on the V slot, then turn the knob to the continuity symbol shown in picture below.
To check continuity between terminals say terminal A and terminal B, place one probe any probe on terminal A and the other on Terminal B. The below video will show how to check for continuity in circuits and how to detect broken connections. One of the most use and unavoidable component in electronics are Resistors. There are a wide range of resistors available based on their power rating and resistance value, the value of each resistor will be mentioned with the help of colour codes.
In those cases we can use a multimeter to read the resistance value of the resistor easily. To measure resistance with multimeter make sure the black probe is on the COM slot and the red probe in on the V slot. Now, turn the knob to the Resistance symbol. You can always try different ranges to get the right range that suits for your resistor.
The below video shows how we can measure the resistance value using multimeter. The value measured will not be accurate; this can just be used as an approximation. Also if the resistor is placed inside a circuit then we should not measure the resistance using multimeter, since it will show wrong values. Another interesting mode in the multimeter is the Diode mode. Think no more get your multimeter place it in diode mode and check it in no time.
You check the polarity of your LED and even make it glow to check for its working. To use the diode mode, make sure your black probe is in the COM slot and the red probe is in the V slot. Now, adjust the regulator knob to the diode symbol as shown in the picture below. This works because LED is also a form of diode, if you reverse the polarity the LED will not glow the same can be used to check the working of a diode. Informative article sharing this article post. Honestly, this is the first time I read the blog article.
But I really satisfied to read your blog article. I need a digital multimeter for my home working. But I am a little bit confused how can I test. But now am clear my all confusion. Thanks for your helpful sharing. Guys would love it.
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