How to Measure Resistance
Choose the item whose resistance you wish to measure., Plug the test leads into the correct test sockets., Turn on the multimeter and select the best testing range., Touch the multimeter leads to the ends of the component you are testing., Turn off...
Step-by-Step Guide
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Step 1: Choose the item whose resistance you wish to measure.
For the most accurate measurement, test the resistance of a component individually.
Remove the component from the circuit or test it before you install it.
Testing the component while still in the circuit can cause inaccurate readings from other components.If you are testing a circuit or even just removing a component, be sure that all power to the circuit is turned off before proceeding. -
Step 2: Plug the test leads into the correct test sockets.
On most multimeters, one test lead will be black and the other will be red.
A multimeter often has multiple testing sockets, according to whether it is being used to test for resistance, voltage, or amperage (current).
Usually the right sockets to test for resistance are labeled "COM" (for common) and one labeled with the Greek letter omega, Ω, which is the symbol for "ohm".Plug the black lead into the socket labeled "COM" and the red lead into the socket labeled "ohm". , The resistance of a component can range from ohms (1 ohm) to megaohms (1,000,000 ohms).
In order to get an accurate reading of resistance you must set the multimeter to the proper range for your component.
Some digital multimeters will automatically set the range for you, but others will need to be set manually.
If you have a general idea of the range of resistance just set it to that range.
If you’re unsure, you can determine the range through trial and error.
If you don’t know the range, start with the middle range setting, usually 20 kilo-ohms (kΩ).
Touch one lead to the end of your component and the other lead to the opposite end.
The number on the screen will either be
0.00, OL, or the actual value of resistance.If the value is zero, the range is set too high and needs to be lowered.
If the screen reads OL (overloaded) the range is set too low and needs to be increased to the next highest range.
Test the component again with the new range setting.
If the screen reads a specific number such as 58, that is the value of the resistor.
Remember to take into account the range applied.
On a digital multimeter the upper right-hand corner should remind you of your range setting.
If it has a kΩ in the corner, the actual resistance is 58 kΩ.
Once you get in the right range, try lowering the range one more time to see if you can get a more accurate reading.
Use the lowest range setting for the most accurate resistance readings. , Just as you did when you were setting the range, touch one lead to one end of the component and the other lead to the opposite end.
Wait until the numbers stop going up or down and record that number.
This is the resistance of you component.
For example, if your reading is .6 and the upper right corner says MΩ the resistance of your component is
0.6 mega-ohms. , When you are done measuring all of your components, turn off the multimeter and unplug the leads for storage. -
Step 3: Turn on the multimeter and select the best testing range.
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Step 4: Touch the multimeter leads to the ends of the component you are testing.
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Step 5: Turn off the multimeter.
Detailed Guide
For the most accurate measurement, test the resistance of a component individually.
Remove the component from the circuit or test it before you install it.
Testing the component while still in the circuit can cause inaccurate readings from other components.If you are testing a circuit or even just removing a component, be sure that all power to the circuit is turned off before proceeding.
On most multimeters, one test lead will be black and the other will be red.
A multimeter often has multiple testing sockets, according to whether it is being used to test for resistance, voltage, or amperage (current).
Usually the right sockets to test for resistance are labeled "COM" (for common) and one labeled with the Greek letter omega, Ω, which is the symbol for "ohm".Plug the black lead into the socket labeled "COM" and the red lead into the socket labeled "ohm". , The resistance of a component can range from ohms (1 ohm) to megaohms (1,000,000 ohms).
In order to get an accurate reading of resistance you must set the multimeter to the proper range for your component.
Some digital multimeters will automatically set the range for you, but others will need to be set manually.
If you have a general idea of the range of resistance just set it to that range.
If you’re unsure, you can determine the range through trial and error.
If you don’t know the range, start with the middle range setting, usually 20 kilo-ohms (kΩ).
Touch one lead to the end of your component and the other lead to the opposite end.
The number on the screen will either be
0.00, OL, or the actual value of resistance.If the value is zero, the range is set too high and needs to be lowered.
If the screen reads OL (overloaded) the range is set too low and needs to be increased to the next highest range.
Test the component again with the new range setting.
If the screen reads a specific number such as 58, that is the value of the resistor.
Remember to take into account the range applied.
On a digital multimeter the upper right-hand corner should remind you of your range setting.
If it has a kΩ in the corner, the actual resistance is 58 kΩ.
Once you get in the right range, try lowering the range one more time to see if you can get a more accurate reading.
Use the lowest range setting for the most accurate resistance readings. , Just as you did when you were setting the range, touch one lead to one end of the component and the other lead to the opposite end.
Wait until the numbers stop going up or down and record that number.
This is the resistance of you component.
For example, if your reading is .6 and the upper right corner says MΩ the resistance of your component is
0.6 mega-ohms. , When you are done measuring all of your components, turn off the multimeter and unplug the leads for storage.
About the Author
Emma Gibson
Creates helpful guides on lifestyle to inspire and educate readers.
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