A digital multimeter is a useful tool that can be used to test electronic components and circuits, learn about electronic designs, and even test a battery. A multimeter also enables you to conduct basic checks and troubleshooting electrical systems at home. Here are some things that you can measure with a multimeter:
Continuity testing is used to test the resistance between two points which lets you know whether they are connected electronically. If there is a low resistance, the two points are continuous, meaning that an electric current can flow freely from one end to the other. A tone is emitted by the multimeter to signify that the points are continuous. Hence, if there is no continuity, it means that there is a break somewhere in the circuit. This test is important and is considered one of the most useful tests for electronic repairs as it enables users to identify if two points are connected when they should not be and vice versa.
Before you conduct this test, take note that it is not advisable for home owners to test for AC voltage as it is more dangerous unless you are an expert. Hence, you should only test for DC voltage – the kind that runs on all consumer electronic devices. To test for DC voltage, first plug the black probe into the COM port on your multimeter and the red port into the mAVΩ port. Then switch on the multimeter and set the dial to DC voltage mode (indicated by a V with a straight line). As most multimeters are not autoranging, you will need to manually set the correct range for the voltage you want to measure. If you are not sure, start with the highest setting.
Once you are done with the setup above, place the red probe on the positive terminal and the black probe on the negative terminal. If the range you set is too high, the multimeter will not show a very accurate reading. If it is too low, the device will simply read 1 or OL, meaning that is out of range. In this case, simply set the dial to a higher range.
Before you begin a resistance test, make sure that no current is running through the circuit or component you want to test. Set up the multimeter by plugging the black probe into the COM port and the red probe into the mAVΩ port. Then, switch on the device and set the dial to resistance mode, represented by the Ω symbol. You need to manually set the range for the resistance you want to measure. Place the probes at each end of the circuit or component you want to test; it does not matter which probe goes where as resistance is non-directional. If the multimeter reads close to zero, the range is too high. If the range is too low or the component is not continuous, the multimeter will simply read 1 or OL.
To protect the electronic products you have at home, you should install these surge protection devices to prevent them from short-circuiting.