Ohms, which are units that describe the amount of resistance between two points on a conductor, are named after Georg Simon Ohm, a19th century German physicist. Ohm discovered that the current that passes through a conductor is proportional to the difference across the two points and inversely proportional to its length, a discovery that was later coined "Ohm's Law." To measure ohms you need a multimeter that can also measure volts and current. Depending on how you've set the multimeter, the decimals that appear in an ohm figure will refer to differing resistances.
Step 1
Determine the approximate ohm value for the item being tested. This value could be listed on a schematic diagram or an owner's manual. If you can't find this value, don't worry; it isn't completely necessary, but it will help you more easily read the multimeter.
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Step 2
Adjust the multimeter to "200 Ohms" if you've determined the item is between 0 and 200 ohms. This option will be present on the side or face of the device. Touch the multimeter's probes to the leads and read the number as it appears. If, for example, the multimeter displays "125.5," you would read that as "one-hundred, twenty-five and a half ohms."
Step 3
Set the multimeter to "2K," "20K" or "200K" if you've determined the item is between 200 and 2000 ohms, 2000 and 20,000 ohms, or 20,000 and 200,000 ohms, respectively. Touch the multimeter's probes to the leads and mentally shift the decimal point three places to the right. If, for example, the multimeter displays "1.5235," you would read it as "one thousand, five hundred and thirty-five ohms." If it displays "15.120," read it as "fifteen-thousand, one-hundred twenty ohms." If it displays "175.550," read it as "one-hundred seventy-five thousand, five-hundred-fifty ohms."
Step 4
Put the multimeter on "2M" if you've determined the item is between 200,000 and 2,000,000 ohms. Touch the multimeter's probes to the leads and mentally shift the decimal point six places to the right. If, for example, the multimeter displays "1.855," you would read it as "one-million, eight-hundred and fifty-five thousand ohms."
Step 5
Choose any setting if you do not know the approximate ohm value of the item. Remember to move the decimal the appropriate number of places to the right. For example, if you are in the 2M mode and the reading is 0.0255, shift the decimal place six places to the right to get 25,500. You would read this as "twenty-five thousand, five-hundred ohms."
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