What’s the use of measuring resistance? To see whether a circuit or component is working properly. The lesser the current flow, the greater the resistance. To regulate circuits, switches and relay contacts have a low resistance that rises over time as a result of things like deterioration (such as wear and dirt). Insulation failure and moisture cause loads like motors and solenoids to lose resistance over time. To determine how much resistance there is:
Turn the circuit’s power supply off.
Do not take a resistance reading until you have discharged the capacitor first.
It’s possible to use a digital multimeter to measure resistance, or ohms, which commonly shares a space on the dial with other types of testing and measuring (continuity, capacitance or diode; see illustration below).
A Digital Multimeter singapore in Resistance mode will begin measuring resistance even before any test leads are attached to a component, therefore the display should show OL instead of OL.
Using open (unattached) test leads may cause the M sign to show on the display.
Using the Autorange mode, a digital multimeter automatically finds the optimal range when the leads are attached to a component.
The Range button may be used by a technician to manually set the range. If the component to be tested is disconnected from the circuit, the best results may be acquired. The measurements might be influenced by other components in the circuit that are connected to the one being tested if the component is left in place. Insert the black test lead into the COM port, then go to step three. The red lead should be inserted into the V jack at this point. Remove the leads in reverse order: red first, black second. Assemble the component being tested and connect the test leads across it.
Make that the test leads and circuit are properly connected.
Use the relative mode for low-resistance readings (REL; see point 11). Zero or Delta () mode are other names for this mode. A normal test lead resistance of 0.2 to 0.5 milliohms is automatically subtracted from this value. Test leads touching (shorting each other) should result in a 0 reading on the display.