Multimeter use - solutions - Huaqiang Electronic Network

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The dial of the multimeter (for example, the 105 type) is shown below. The measurement items and measurement ranges are changed by the knob of the changeover switch. The mechanical zero knob is used to keep the pointer at the left zero position at rest. The “Ω” zero adjustment knob is used to measure the resistance so that the pointer is aligned to the right zero position to ensure accurate measurement values.

The measuring range of the multimeter is as follows:
DC voltage: divided into 5 files? 0-6V; 0-30V; 0-150V; 0-300V; 0-600V.
AC voltage: 5 files? 0-6V; 0-30V; 0-150V; 0-300V; 0-600V
DC current: divided into 3 files? 0-3mA; 0-30mA; 0-300mA.
Resistance: divided into 5 files? R*1; R*10; R*100; R*1K; R*10K Measuring resistance: - first short the table rod together, so that the pointer is turned to the right, then adjust the "Ω" zero adjustment knob so that the pointer just points to 0. Then, the two rods are respectively contacted with the two ends of the measured resistance (or circuit), and the reading of the pointer on the ohmic scale line (the first line) is read, and then the number of the index is multiplied, which is the resistance value of the measured resistance. . For example, the resistance is measured by R*100, and the pointer is at 80, and the measured resistance is 80*100=8K. Since the left side of the “Ω” tick is densely read and difficult to see, the appropriate ohms should be selected for the measurement. Make the pointer in the middle or right of the tick mark so that the readings are clear and accurate. Each time you change gears, you should short-circuit the two bars and re-adjust the pointer to zero to measure. Measure DC voltage:--First estimate the magnitude of the voltage to be measured, then turn the transfer switch to the appropriate V range, connect the positive bar to the "+" terminal of the measured voltage, and the negative bar to the measured voltage "-" terminal. . Then, according to the number of the range and the number indicated by the pointer on the standard DC symbol "DC-" scale line (second line), the magnitude of the measured voltage is read. If you measure with V300 volts, you can directly read the indication value of 0-300. If you use V30 volts measurement, you only need to remove a "0" from the digit on the scale line 300, which is regarded as 30, and then treat the numbers such as 200 and 100 as 20, 10 and directly read the pointer indication value. For example, the V6 voltage is used to measure the DC voltage, and the pointer is at 15, the measured voltage is 1.5 volts. Measure DC current: -- Estimate the current to be measured first, then turn the switch to the appropriate mA range, and then connect the multimeter in the circuit as shown. At the same time, observe the tick mark marked with the DC symbol "DC". If the current range is selected in the 3 mA range, then the number on the surface tick mark 300 should be removed from the two "0"s, which is regarded as 3, and then 200. 100 is regarded as 2, 1, so that the measured current value can be read. For example, the DC current is measured with a DC 3 mA range, and the pointer is at 100, and the current is 1 mA.
Measuring AC voltage: The method of measuring AC voltage is similar to measuring DC voltage. The difference is that there is no positive or negative difference in AC power. Therefore, when measuring AC, the meter bar does not need to be positive or negative. The reading method is the same as the above-mentioned reading of the measured DC voltage, except that the number should be the position of the pointer on the scale line marked with the AC symbol "AC".