How To Use A Digital Multi Meter
DMM Functions - Ohm Meter
The Ohm Meter function is used to test the resistance of a device. This is a more detailed reading than the simple good/bad result you get from a continuity tester. Sometimes the device you are testing is designed with so much resistance in it that it will fail a continuity test even though it is still good and the circuit is complete. Some examples of this are the copper winding in an electric motor, a glow bar igniter or the heating element of an electric stove.
To use this function, place the leads of the DMM in the appropriate slots, generally marked as 'COM' for the ground or common lead (black) and with the Greek letter Omega for Ohms or resistance. Then adjust the dial, if necessary, to the level above the highest expected level of resistance. If you are simply checking for continuity through the device, then set the DMM for 100 Ohms.
Touch the probes to either contact of the device and note the reading on the meter. If the meter reads 'Infinite Resistance' and it uses a dial, then move the dial up to the highest setting and test the device again. If it still reads the same, then the device has failed the test.
