Often we need to test whether a circuit is open or closed. This test helps us to determine the continuity or usability level of that circuit. For example – you will see a wall switch is closed even if it is turned to the ‘On’ position. On that contrary, it will be open when it is lit. Typically, an open circuit is not able to conduct electricity, but a closed circuit has continuity.
For this reason, when you are trying to test the continuity of a circuit, you should test it when the current is not present. Before starting your test, you should also unplug the device, or you can turn off main circuit breaker. Another issue that you must remember is to check all equipment before the continuity test.
Now, to conduct a continuity test, you will require a multimeter or a continuity tester (a very simple device that will light up to show the continuity). When you are testing with a multimeter, you have to set it to the OHM setting, denoted by, Greek letter omega. In case, you see more than one OHM setting; you can select X1.
Continuity Test: An Overview
- The term continuity refers to the presence of current in a complete manner. A circuit is complete when the switch is closed.
- With a digital multimeter, you can test fuses, switches, electrical connections, conductors, and many other components.
- When a complete patch for current flow is detected, a DMM will emit an audible response (like a beep).
- This audible response or beep allows the technicians to concentrate on further testing procedures without worrying about the display of a multimeter.
- The rule of thumb for a continuity test is that a multimeter will beep. This audible response is based on the resistance of component that is used for testing. You can determine the resistance of the component by using the range setting of the multimeter. For example – for a range of 400.0 Ω, a multimeter will beep if the element possesses a resistance level of 40 Ω or less
- If a testing circuit component has a low-resistance value like electrical connections, you must use the lowest possible range setting.
How To Test for Continuity?
To test the continuity, perform the following procedures –
- First of all, you need to turn the dial to Continuity Test Mode. It will show a spot on the dial with more than one option, typically resistance (Ω). Since the test probes are separated, the display of the multimeter might show OL and Ω.
- Secondly, depending on the necessity, you might press the continuity button.
- Now, you can insert the black test lead into the COM jack. Then add the red lead into the V Ω jack. When you are finished with testing, you can remove the leads in reverse order such as red lead in the first and the black one in the second.
- At this stage, as the circuit is de-energized, you can connect the test leads to the component that is being tested. Remember that the position of the test leads is always going to be arbitrary. Besides, you might need to isolate the component from other components of the circuit as well.
- When the multimeter detects a complete path for current flow, it will deliver an audible response like a beep. In case the circuit is open, the multimeter will not beep.
- Finally, when you have finished testing with a multimeter, don’t forget to keep the multimeter off. In this way, you can preserve the battery life for an extended period.
The bottom line is you can use a simple continuity tester to conduct this test. Compared to a digital multimeter, this device is less expensive. All in all, using a digital multimeter for testing continuity is incredibly easy, and if you follow the above procedures, you won’t encounter any difficulty!