How to read ohms on a multimeter?
Measuring resistance on a multimeter can be really easy with some very simple steps. Resistance, otherwise known as ohms, is needed to be measured for many reasons. You may want to check resistance in order to see the accuracy of a resistor. Or you may not know the resistance of a circuit and want to know what it is. Most circuits are color coded which makes it easy to determine their resistance, but in any case, you can always check this using your multimeter.
No matter what your reason for measuring resistance, your digital multimeter is a great piece of equipment to do it with. You can utilize most of the Fluke brand devices to measure resistance including some of my favorites like the Fluke 116, Fluke 117, Fluke 87V, or Fluke 3000 FC.
What you will need:
- Digital Multimeter with the ohms setting Ω, like Fluke 116 (see on Amazon.com)
- A socket or the item to be measured
How to Measure Resistance
There are a few simple steps to measure resistance with your digital multimeter:
- Pick the item you want to measure where resistance may be found.
- Select the appropriate ohms setting which you will know it because the section will show this sign: Ω
- You may not know right away which range to use when selecting the ohms setting, but if later on when you start to measure your multimeter show something strange like a 1 and a bunch of blank spaces (like this: 1__._), you’ll know that it’s too low and you’ll have to increase the range.
- For the probe leads, you’ll need to modify them when measuring resistance. The black lead will stay in the socket that says COM which is normal. For the red probe lead, you’ll need to make sure it’s put in the socket which shows the ohms symbol (Ω).
- Next, you’ll want to test if the meter is functioning properly by taking your red and black probe leads and touch the metallic parts together. The multimeter should say almost zero, but usually will say 1 or 2. If your multimeter shows a high number, then something is wrong with your multimeter and you probably will not have accurate results.
- Again, make sure your resistor is not connected to any circuit or power source.
- Take your black and red lead and connect them to opposite ends of the object you are looking to check resistance on (the resistor).
- Your device will then show you a number which is your resistance.
Things You Should Know
There are a few different setups that you may have when doing resistance measurement so it’s important to know the following:
- Disconnect Object: Before you can start measuring resistance, you need to make sure that there is no electricity flowing through an object. If electricity is flowing through it, it will not measure resistance properly. First disconnect the device from any power source prior to testing its resistance.
- Remove from Circuit: Another important reminder is to ensure that the device/resistor is not a part of a circuit as well. It is best to remove the resistor from the circuit prior to testing it for resistance as the additional paths within the circuit will affect the results of the resistance as they will have resistance as well.
- Analog Meter: If you are using an analog multimeter, the steps are the same in both instances, but the device may look different with the needle showing you the actual measurement.
Resistance is an easy measurement to make. If you’re looking for an instructional video, this one is great to check out:
It’s always important when you’re finished making your measurement to turn the multimeter off as when it is put in this setting an electrical charge is being sent constantly through the probes. As well if you need your readings saved, many multimeters have a “hold” button which will save the reading if you need to refer back to it at a later time.