Maintenance precautions for the use of a multimeter
1) Before using a multimeter, a mechanical zero adjustment should be performed, which means that when there is no measured electricity, the pointer of the multimeter should be placed at zero voltage or zero current.
(2) During the use of a multimeter, do not touch the metal part of the probe with your hands. This not only ensures accurate measurement, but also ensures personal safety.
(3) When measuring a certain amount of electricity, it is not advisable to shift gears simultaneously, especially when measuring high voltage or high current. Otherwise, it will damage the multimeter. If you need to shift gears, you should first disconnect the probe and then measure it after shifting gears.
(4) The multimeter must be placed horizontally during use to avoid errors. At the same time, attention should also be paid to avoiding the influence of external magnetic fields on the multimeter.
(5) After using the multimeter, the conversion switch should be placed in the * high gear of the AC voltage. If not used for a long time, the battery inside the multimeter should also be removed to prevent the battery from corroding other components inside the meter.
How to judge the quality of piezoelectric ceramics with a multimeter
Piezoelectric ceramics are artificially synthesized piezoelectric materials. When subjected to external pressure, charges are generated on both sides, and the amount of charge is proportional to the pressure. This phenomenon is called the piezoelectric effect. Piezoelectric ceramics have a piezoelectric effect, that is, under the action of an external electric field, they will undergo deformation, so piezoelectric ceramic sheets can be used as sound emitting components.
By utilizing the piezoelectric effect of piezoelectric ceramic sheets, a multimeter can be used to determine their quality.
Lead out two wires from the two poles of the piezoelectric ceramic sheet, then place the ceramic sheet flat on the table, connect the two wires to the two probes of the multimeter, set the multimeter to the low current range, and gently press the ceramic sheet with a pencil eraser. If the pointer of the multimeter swings significantly, it indicates that the ceramic sheet has led out two wires from the two poles of the piezoelectric ceramic sheet. Then place the ceramic sheet flat on the table, connect the two wires to the two probes of the multimeter, set the multimeter to the low current range, and gently press the ceramic sheet with a pencil eraser. If the pointer of the multimeter swings significantly, it indicates that the ceramic sheet is intact. Otherwise, it indicates that it is damaged.
Intact, otherwise it indicates damage.
