Guidelines for Verifying Circuit Continuity with a Multimeter
Step 1: Preparation work
Firstly, ensure that the circuit under test is in a disconnected state. If the circuit under test is a closed circuit, it is necessary to open the switch or disconnect the power supply to ensure that current cannot pass through.
Step 2: Connect the wires
Then, connect the black cable (i.e. ground wire) of the multimeter to the common or negative connection point of the circuit, and connect the red cable (i.e. measuring end) to the desired measurement line in the circuit.
Step 3: Adjust the knob
Next, adjust the current range gear on the multimeter selection knob based on the estimated range of the current to be measured. Usually, the starting gear should be greater than the required measured current to avoid burning out the multimeter or causing other safety issues.
Step 4: Close the circuit
Next, close the circuit under test by pressing the switch or reconnecting the power supply to start the current flow. At this point, the multimeter can display the current value through the measured circuit.
Step 5: Read the current value
Wait for a few seconds until the pointer or number on the multimeter stabilizes, then the measured current value can be read. If a digital multimeter is used, the current value will be directly displayed on the instrument; If using an analog multimeter, it is necessary to carefully observe the position of the pointer to ensure accurate readings.
Step 6: Turn off the circuit
After the measurement is completed, remember to turn off the circuit under test to avoid power consumption or other accidents.
How to use a multimeter to measure whether a circuit is connected or not
A multimeter can also be used to check the connectivity of a circuit, that is, to confirm whether a circuit is unobstructed. The following are the
steps to measure whether a circuit is connected or not using a multimeter.
Step 1: Preparation work
Similar to measuring current, first ensure that the line or circuit to be tested is in a disconnected state and take necessary protective measures, such as disconnecting the power supply or turning on relevant switches.
Step 2: Select Mode
Adjust the selection knob of the multimeter to the resistance measurement mode, usually the gear marked with Ω. In this mode, the multimeter can measure the resistance value of a circuit or wiring.
Step 3: Connect the wires
Connect the two probes of the multimeter to the two pins (or two test points) of the circuit under test, with one contact located at the test end connected to the black cable and the other at the test end connected to the red cable. Ensure that the probe is tightly held to ensure good contact.
Step 4: Read the resistance value
Wait for a few seconds until the pointer or number on the multimeter stabilizes, then the measured resistance value can be read. If a digital multimeter is used, the resistance value will be directly displayed on the instrument panel; If using an analog multimeter, it is necessary to carefully observe the position of the pointer to ensure accurate readings.
Step 5: Determine connectivity
Determine whether the circuit is unobstructed based on the measured resistance value. If the measured resistance value is close to zero, it indicates that the circuit is unobstructed; If the measured resistance value is very large or infinite (displayed as ∞), it indicates that the circuit is not connected.
It should be noted that when using a multimeter to measure circuit connectivity, there may be other components or parts in the circuit, and the resistance values of these parts may also affect the measurement results. Therefore, before measuring, we should understand the overall structure of the circuit in order to correctly comprehend and interpret the measurement results.
