The people with electrical backgrounds already know well how to read multimeters and their symbols but beginners and students may get confused while reading them. So this guide is basically for people who don’t know much about multimeter usage. We’ll try to cover all necessary topics to clarify to you how multimeters generate reading and how to evaluate final results.
Although reading basic multimeter functions like voltage and current doesn’t need deep technical knowledge but there are some tips and metering factors for parameters like ohms, capacitance, milli volt, and milliamps etc. With a little learning, everyone can master meter readings.
How to read a Multimeter
The first step for reading a multimeter is to understand its symbols and ranges well. You should know ac/dc difference, auto, and manual range options, and the difference between kilo, milli, mega and micro readings. Actually, it’s all about decimal setting, we get all results in form of some number and have to adjust them according to their decimal values.
Here we can take an example of millivolts, there are 1000 millivolts in 1 volt. Suppose, if we have to convert and show1 milli volt into volts then the value will be 0.0001 volts. That’s how decimal value difference works in multimeter reading.
There’s also some difference between analog and digital multimeter reading conclusions. In analog, we have to do some more effort by calculating decimal values manually while digital meters do this task automatically and provide us immediate results.
How to read Voltage on a Multimeter
Reading voltage values by a multimeter is the simplest task we all know. One only has to adjust the meter dial to ac or dc voltage according to requirement, connecting testing leads to the source and seeing result on display.
For voltage multimeter will show values like 400 v ac , 210 v dc , 12v dc etc. Just remember one thing here that always set multimeter on a higher range than the values you are measuring.
How to read current/amps on Multimeter
Digital multimeters usually come with a lower range of current measurement from 10A to 20A. For large current digital clamp meters are the best devices because they provide safety and accuracy at their best. Readings amps in dmm are simple, result come with a symbol of ac and dc that means amperes.
Some multimeters have a resolution of milli and micro amps denoted by ma and µa respectively. 1 amp is equal to 1000 milli amps and 1000000 micro amps. If one wants to test a lower value of current then adjust the meter on milli or micro range setting.
How to read resistance value on the Multimeter
Reading an ohms value on a multimeter is little bit tricky due to large resistors values and more range availability. First step of testing a resistor is to conclude the resistor value manually by coding method if we don’t know its actual rating. Suppose if value is 870 ohms, now set the multimeter to a higher value range than 870.
We may set meter on 2000 ohms range, connect test leads with resistor and see reading. Reading should be somewhat between 860 to 880 ohms if the resistor is in good condition. Now for learning set range to 200 ohms and you’ll find no results on the screen. It’s because the adjusted range of 200 is much lower then resistor you’re testing so meter can’t calculate its value.
If we set a more high range like 2k ohms reading will be like 0.87 which actually means 0.87 k and if the setting is adjusted on 200k reading will be like 0.8 which means 800 ohms or more. It sounds confusing but with some exercise, you’ll be an expert on it.
How to read an Analog Multimeter
Reading an analog multimeter is different from a digital one. In analog meters result is shown through a needle pointing on scales. Typically they come with three scales that are for separate parameters that’s why new people may get confused.
First and lower one scale is for db (decibels) value, AC is for ac voltage, DC for dc voltage reading, Ω is for resistance measurement. Some analog multimeters also have additional functions like capacitance, micro amps and milli amps current measurements. These are denoted by their signs on the right side of the scale respectively.
Reading voltage on Analog Multimeters
After adjusting meter switch to dc or ac voltage, connect probes to the source you want to analyze. Now carefully see row having ac or dc voltage scale, it’s generally on the second row after ohm. Now if you are testing 24v set meter on 50 or 100 volts.
After connecting meter to the power source check needle movement on screen, you have to count scale lines manually here. For example, if there are 4 lines in between 0 to 50v that means every line will indicate a change of 10v. Similarly, if there are 3 lines between 50 to 70, it indicates 55, 60, and 65 v.
How to read resistance on an Analog Multimeter
Check analog multimeter dial you’ll find that the resistance range is different from other parameters. Rather than magnitude, the range is defined in form of multiples here like cross 10, 100, 1k, and 100k. It gives us a multiple of reading, if the needle is at 15 ohm while range was set on multiple of 10, then reading will be 15 * 10 = 150 ohms.
If the reading you get was 50 and range is set on 100 then result will be 5000.
There are only two things important in correct way of reading a multimeter, which are focus and numbers/symbols knowledge. With a little effort and training, everyone can do it well. We’ll suggest you that never try these things without enough education and safety training. We hope that this basic level guide helped you in understanding how to read a multimeter.
Leo Maxwell is basically an Electrical engineer and hobby tech writer, having 13 years of experience in the electronics and instrumentation industry. He has hands on experience working in various fields like Powerhouses, solar, automotive, and FMCG.
During his career, he has used many power tools and meters in electrical projects. Now his aim is to explain tools and troubleshooting in easy guides to help people. Other then it, leo loves traveling, reading books and DIY tasks.