When the multimeter is measuring high voltage, forgetting to change the gear will burn the multimeter. For example, use the resistance gear to measure the 220v voltage. Some multimeters have anti-burn protection function, so we must first select the gear range when using the multimeter. Then go to measure, don't blindly pick it up and use it. When not in use, we have to adjust the multimeter to the highest voltage level, or to the off file, in case you forget to adjust the file and burn out the multimeter. Do not charge the components when measuring To measure, especially the power supply line above 220v, be sure to cut off the power when measuring the on-off of the line.
As long as the multimeter can be used normally as required, the service life is quite long. If you don’t know the voltage when measuring the voltage, you should put the highest gear first. Every time the test pen touches the measuring point, you must first check the gear, so as to prevent the on-off measurement after the measurement. The voltage and the meter are still in the ohm range. In short, develop good usage habits, and the life of the multimeter is very long.
There are several reasons why the multimeter burns.
1. Hit the resistance gear to measure the AC, this is very dangerous, the meter will burn immediately.
2. When measuring the AC voltage, hit the small voltage gear to measure the high voltage, and the watch will also burn at this time.
3. Insert the test lead into the current measurement jack, if it is not changed to the voltage measurement jack, hit the voltage gear to measure the voltage.
4. The current measurement must be connected in series with the load and the multimeter can only measure small currents, so the meter will burn if it is not connected in series. Even if it is connected in series, the meter will burn if the current exceeds the current. However, with the advancement of technology, some multimeters already have reliable protection. device, reducing the possibility of burning the watch.
(1) Low voltage block to measure high voltage.
(2) Small current block to measure large current.
(3) Current block and measure voltage.
(4) The electrical barrier measures the voltage and current.
Today's multimeters all have protection functions. There are three fuses in the back shell, which are voltage and current resistance. The fuse to protect against misoperation is broken. If it's a pointer, it may burn the dial or hands. Because the instantaneous voltage and current were too large, the fuse did not have time to break. A broken fuse can only be considered a minor fault, and a broken circuit board is considered a burnt.
