How to use a multimeter to measure AC and DC current
Measure AC voltage with a digital multimeter: Connect the black probe to ground (indicated in the probe socket) and the red probe to the AC (or V letter plus one~) hole; The gear refers to the range of 750 (some are 1000) in the AC~column (if measuring 220V mains power). Then touch the two holes of the power socket separately, and the reading is the AC voltage value.
Using a pointer meter to measure AC voltage: Connect the black probe to negative or ground, connect the red probe to+, set the gear to AC~500V, insert two probes into the same digital multimeter for measurement, and read the number pointed by the pointer corresponding to the maximum range on the right side: that is, if the 500V gear is selected, the reading should look at the row marked with the maximum number on the right side of the reading disc as 50. If the pointer points to 20, then the reading is 200V.
Digital multimeter for measuring DC voltage: When measuring AC voltage, only the red pen is connected to the+hole, and the red pen is also connected to the+pole of the power supply. The gear is set to DC (or a short horizontal line under the letter V), and the range depends on the specific situation, from large to small. For example, when testing a No. 5 battery, choose a 2V range. If the polarity is reversed, there will be a negative display before the reading.
Measuring DC voltage with a pointer multimeter: using the same digital multimeter measurement method, the reading is the same as measuring AC voltage as described above; When the positive and negative poles of the DC voltage cannot be determined, it can be measured as AC voltage first, but the reading is not concerned. Only the polarity of the probe is reversed and measured to see which of the two measurements the pointer needs to deflect. Then, the probe is in contact with the correct positive and negative polarity. Then shift the gear to the appropriate range of DC voltage and measure the reading.
Introduction: Proper use can not only quickly and accurately identify the faulty part, but also prevent damage to electrical equipment and the multimeter itself. 1. When measuring, first look at the gear. If you don't look, don't measure. Every time you pick up the probe to prepare for measurement, be sure to double check the measurement category
