14 unique techniques used by the multimeter (I)

We all know that the multimeter is a common maintenance tool that is indispensable for the work of electrical workers. Proper use of the multimeter can not only make our work more efficient, but also improve the safety and efficiency of our work.

1. Before using the multimeter, first perform "mechanical zero adjustment";

2. Do not touch the metal part of the test pen by hand during the measurement process, which not only ensures the accuracy of measurement, but also ensures personal safety;

3. In a complex environment, it is necessary to pay attention to the influence of external magnetic fields on the multimeter;

4. In order to improve the measurement accuracy, try to make the pointer of the multimeter in the middle position during the measurement. The range should be appropriate and the needle should be over halfway. If you can't estimate the measured size beforehand, you should try to select a larger range, and then gradually change to a smaller range according to the deflection angle, until the pointer is deflected to about 2/3 of the full scale;

5. When testing a positive or negative polarity component such as a transistor or an electrolytic capacitor with a multimeter, pay attention to the polarity relationship. The black negative should be remembered, and the black inside the table is "+". The red test pen is the positive pole, and the black test pen is the negative pole, but the black gauge pen is connected to the positive pole of the internal battery;

6. If the multimeter needs to shift gears, the pen should be disconnected first, and then measured after shifting. The measurement is not dialed, and the neutral is measured. The selection knob cannot be arbitrarily adjusted during the measurement, especially when measuring high voltage (such as 220V) or high current (such as 0.5A) to avoid arcing and burning the changeover switch contacts. After the measurement is completed, the range selection switch should be set to the "•" position;