Methods and steps for measuring current with a desktop digital multimeter
I. Introduction
The desktop digital multimeter is a multi-functional, multi-range measuring instrument that is widely used in electronics, electricity, home appliance maintenance and other fields. It has the advantages of high measurement accuracy, complete functions, and simple operation. During electrical maintenance, we often need to measure the current in the circuit to ensure the normal operation of the circuit. This article explains how to measure current using a benchtop digital multimeter.
2. Preparation work
Turn off power: Before making current measurements, power to the circuit must be turned off to avoid the risk of electric shock.
Connect the multimeter: Connect the multimeter correctly to the circuit under test. Under normal circumstances, the red test lead of the multimeter should be connected to the high voltage terminal, and the black test lead should be connected to the low voltage terminal. For AC circuits, there is no need to consider voltage polarity.
3. Select the measuring range
Observe the size of the current: Before measuring the current, we need to observe the size of the current in the circuit in order to select the appropriate range.
Select the measuring range: Select the appropriate measuring range according to the current in the circuit. For situations where the magnitude of the current is unknown, we should choose the maximum range to ensure the accuracy of the measurement
4. Measurement steps
1. Correctly connect the multimeter to the circuit under test and set the selector switch to the appropriate current level.
2 Disconnect power from the circuit to avoid the risk of electric shock.
Connect the multimeter in series with the circuit under test, connect the red test lead to the positive terminal of the power supply, and the black test lead to the negative terminal.
3 extreme. For AC circuits, there is no need to consider voltage polarity.
4 Reconnect the circuit power and observe the multimeter reading. If the reading is too small or out of range
Range, you can adjust the range selector switch.
5 Record multimeter readings and record and analyze data as needed.
5. Things to note
1. When using a multimeter for current measurement, safety operating procedures should be followed to ensure the safety of the operator.
2. When measuring large currents, appropriate wires should be used to connect the multimeter and the circuit under test to avoid burning the multimeter or other safety accidents caused by excessive current.
3. Before using the multimeter, you should check whether its appearance and function are normal to ensure the accuracy of the measurement.
4. When making measurements, external interference should be avoided as much as possible to ensure the reliability of the measurement results.
5. When using a multimeter, care should be taken to keep it clean and maintained to ensure its service life and accuracy.
