How to avoid short circuits when measuring the voltage of various circuits on a circuit board with a multimeter
Before measuring any electronic components in a circuit with a multimeter, make sure to check the status of the multimeter. For example, when measuring DC voltage, be sure to set the multimeter to the DC voltage level. If you don't know how high the circuit voltage is, first set the multimeter to the highest level. If measuring AC voltage, it is necessary to set it to the relevant AC gear. If the voltage level is unknown, it is the same to first set it to the highest gear for measurement. After measuring the data at the highest gear, adjust the gear as needed for precise measurement. Remind everyone to check the status of the multimeter to prevent some people from directly measuring voltage when the multimeter is in the resistance or capacitance range, which may cause a short circuit and burn out things. So before measuring anything, it is necessary to develop a habit of checking the gear status of the multimeter and confirming that it is correct before measuring.
1. Sharp multimeter tip as possible
When I was still in school, I followed a habit of my senior brother, which was to polish the metal tips of all my multimeter probes very sharply. The sharp multimeter tip can minimize the contact area with the circuit board, and for measuring small surface mount components, it can prevent the tip from being too thick and accidentally touching adjacent contacts. If you are afraid that the polished pen may oxidize easily, some merchants have already thought of selling pointed gold-plated pens.
2. Find extra black pens and transform them into crocodile clips
Find an extra pair of probes, cut open the black probe with the end in hand, and use a crocodile clip to weld it on for later use. Of course, if you don't want to make it yourself, you can buy ready-made ones, including red and black pens.
To measure the voltage of a circuit board, first determine whether the part to be measured is a DC voltage or an AC voltage. If it is a DC voltage, set the multimeter to the DC voltage measurement mode, and then hold a black pen in one hand and a red pen in the other hand. The black pen is the grounding terminal, and try to find a nearby grounding point that is easy to contact. Generally, circuit boards with larger grounding points are used. Separate the red pen to measure the circuit that needs to be measured. At this point, the sharper the multimeter tip, the more convenient it is to measure some fine surface mount component circuits. If it is inconvenient for both hands to hold the probe separately, then as we mentioned earlier, a spare probe with a crocodile clip can be used. Connect the black probe with a crocodile clip, clamp the crocodile clip to the grounding point of the circuit board, and the red probe can measure the entire DC circuit freely.
