(1) Before using the multimeter, first perform "mechanical zero adjustment", that is, when there is no measured power, make the pointer of the multimeter point to the position of zero voltage or zero current.
(2) In the process of using the multimeter, the metal part of the test pen cannot be touched by hand, so that on the one hand, it can ensure the accuracy of the measurement, on the other hand, it can also ensure personal safety.
(3) When measuring a certain amount of electricity, it is not possible to change gears while measuring, especially when measuring high voltage or high current. Otherwise, the multimeter will be destroyed. If you need to change gears, you should first disconnect the test leads, and then go to measure after the gear shift.
(4) When using the multimeter, it must be placed horizontally to avoid errors. At the same time, we must also pay attention to avoid the influence of external magnetic field on the multimeter.
(5) After using the multimeter, the transfer switch should be placed in the maximum range of AC voltage. If it is not used for a long time, the battery inside the multimeter should also be taken out to prevent the battery from corroding other devices in the meter.
When measuring the DC with a digital multimeter
1. Perform mechanical zero adjustment.
Second, select the appropriate range gear.
3. When using a multimeter current block to measure the current, the multimeter should be connected in series in the circuit under test, because only the series connection causes the current flowing through the ammeter to be the same as the current of the tested branch. When measuring, the tested branch should be disconnected, and the red and black test leads of the multimeter should be connected in series between the two points where the quilt is disconnected. In particular, it should be noted that the current transcription can be connected to the quilt test circuit. This is very dangerous, and it is easy to burn the multimeter.
4. Pay attention to the polarity of the measured power.
5. Correct use of scales and reading.
6. When the 2.5A block with DC current is selected, the red meter pen of the multimeter should be inserted into the 2.5A measuring jack, and the range switch can be placed on any range of the DC current block.
7. If the DC current measured by the quilt is greater than 2.5A, the 2.5A gear can be expanded to 5A gear. The method is very simple. The user can connect a 0.24 ohm resistor between the "2.5A" jack and the black test lead jack, so that the gear becomes a 5A current gear. The 0.24A resistor connected should use a wire-wound resistor of more than 2W. If the power is too small, it will be burned.
The above information is compiled by Shanghai Automation Instrumentation Co., Ltd., I hope it can help you. Shanghai Automation Instrumentation Co., Ltd. is a professional company focusing on instrument sales and instrument maintenance in the field of electronic testing and industrial testing. Provide customers with "rich selection of test products, complete system test solutions, professional test software development, comprehensive technical support and after-sales service." At present, the company mainly sells and maintains electronic test instruments, and develops self-developed products. It has become one of the largest comprehensive instrument service providers in the northwest region.