How to test electronic components using a multi-meter

How to test electronic components by using a multimeter and how to use a multimeter

The electronic components can be tested with the help of a multi-meter and the multimeters are of two types they are digital and analog multimeter. The digital multimeter displays values which are numbers while checking an electronic component, while the analog multimeter has a pointer to point to the value. The below image shows the images of an analog and digital multimeter. Mostly the multimeters have rotary selectors, with the help of these rotary selectors we can select the function and range. An example of this is if we need to check a resistor we can change the function and range to the required ohms with the help of a rotary selector.

We must know how to operate a multimeter otherwise we won’t able to check any electronic component properly. So before measuring anything we must know certain factors such as if we must check the voltage then the AC or DC range must be selected according to the supply, in case if we need to check resistance the ohms range must be selected. The important factor that must be considered while using a multimeter is that we must set the range of voltage and current to a maximum value. If there is an OL displayed in a digital multimeter while checking then we must know that the source that we measured is beyond our set value and an ‘OL’ refers to overload.

How to check resistors

A resistor is a device that can resist or decrease the current in a wire. The properties of resistance are calculated by using ohm’s law. Each resistor has a color code and the color code refers to its resistance. A resistor will be capable to provide the required voltage drop. In order to check the resistor set the ohm’s scale and then set range approximately to your assumption value according to the color code and the resistance, the resistance range must not be set very low.


How to check capacitors

A capacitor is a passive component with a dielectric in the center of it which separates a pair of conductors. Before checking the capacitors it must be discharged, in order to check the capacitor select the resistance range in the multi-meter and the leads of the multimeter must be connected to the capacitor terminals. If the capacitor is damaged then the reading will be very low. But for certain types like electrolytic capacitors when we connect the leads of the multimeter to it at first it would show low resistance and after that, the resistance will increase and that means the capacitor is in good condition.


How to check a diode

Diodes are constructed with semiconductor material and it has two parts they are anode and cathode. The anode is the positive section and cathode is the negative section. The major characteristic of a diode is that it has high resistance in one direction and in other directions, it will be very low. In order to test the diode connect the multi-meter leads to the diode terminal and while doing this we must check the forward and reverse biased condition to know if the diode works or not. So if the diode shows low resistance in forward biased, condition, and high resistance in reverse biased condition then the diode is operational.


How to check a transistor

Transistors are active electronic components it can do amplification and is also used as a switching device. The transistors are mostly constructed by using silicon or germanium. In order to check the transistor set the resistance range in the multi-meter. Connect the probes of the multi-meter to the transistor the positive part of the multimeter must be connected to the emitter section and the base of the transistor should be connected to the negative section of the multimeter. In this case, we could get the readings like low resistance for forward-biased and high resistance for the reverse bias section. If the transistor is damaged then the resistance between any pair of the terminals would be lower than 10 ohms.


How to check a fuse and a coil

In order to check the fuse and the coil set the multimeter to resistor range and connect the leads of the multimeter to the fuse and if there is no reading then the fuse is damaged. Do the same for the coil and if there is no reading then it is damaged.


How to check IC’s

IC’s are integrated circuits and it has transistors, diodes, and resistors in it. It is very difficult to test the IC. Set the multimeter to continuity, the red lead of the multimeter must be connected to the ground of the IC and use the black lead of the multi-meter to check it. So while doing this we would get readings and in certain cases, we could hear a sound from multimeter and it means that the IC is damaged. An IC can also be checked by checking its temperature, if the IC is heating up very fast then it is damaged.