Introduction to the use of a pointer multimeter
A general pointer multimeter changes the measurement items and range through the knob of the conversion switch. The mechanical zero adjustment knob is used to keep the pointer stationary and in the left zero position. The "Ω" zero adjustment knob is used to align the pointer with the right zero position when measuring resistance to ensure accurate measurement values.
The measurement range of a pointer multimeter is as follows:
·DC voltage: divided into 5 levels -0-6V; 0-30V; 0-150V; 0-300V; 0-600V.
·AC voltage: divided into 5 levels -0-6V; 0-30V; 0-150V; 0-300V; 0-600V.
·DC current: divided into three levels -0-3mA; 0-30mA; 0-300mA.
·Resistance: divided into 5 levels - R * 1; R * 10; R * 100; R * 1K; R * 10K.
The specific operation method is as follows:
Measure resistance: First, short circuit the meter bars together, causing the pointer to deflect to the right, and then adjust the "Ω" zero adjustment knob to make the pointer exactly point to 0. Then, contact the two measuring rods at both ends of the measured resistance (or circuit), read the pointer on the first line of the ohm scale, and multiply it by the number on the scale to obtain the resistance value of the measured resistance. For example, when measuring resistance in R * 100 gear and the pointer is at 80, the measured resistance value is 80 * 100=8K. Due to the dense reading on the left side of the "Ω" scale, it is difficult to accurately determine, so an appropriate ohm range should be selected for measurement. Place the pointer in the middle or right of the scale line, so that the reading is clearer and more accurate. Every time you shift gears, you should short circuit the two gauge rods again and adjust the pointer to the zero position to accurately measure.
Measure DC voltage: First estimate the magnitude of the measured voltage, then turn the conversion switch to the appropriate V range, connect the positive meter rod to the "+" terminal of the measured voltage, and the negative meter rod to the "-" terminal of the measured voltage. Then read the magnitude of the measured voltage based on the range number and the number indicated by the pointer on the scale line (second line) of the standard DC symbol "DC -". If measuring with a V300 volt range, the indicated value of 0-300 can be directly read. If using the V30 volt range for measurement, simply remove a "0" from the number 300 on the scale line and consider it as 30. Then, sequentially consider the numbers 200, 100, and so on as 20, 10 to directly read the pointer indication value. For example, when measuring DC voltage using the V6 volt range and the pointer is at 15, the measured voltage is 1.5 volts.
Measure DC current: First estimate the magnitude of the measured current, then turn the conversion switch to the appropriate mA range, and then connect the multimeter in series in the circuit, as shown in the figure. At the same time, observe the scale line marked with the DC symbol "DC". If the current range is selected at 3mA, the number 300 on the surface scale line should be removed from the two "0s" and regarded as 3. Then, 200 and 100 should be regarded as 2 and 1 in order to read the measured current value. For example, if the DC current is measured at 3mA level and the pointer is at 100, the current is 1mA.
Measuring AC voltage: The method of measuring AC voltage is similar to measuring DC voltage, but the difference is that AC does not have a positive or negative distinction, so when measuring AC, the meter rod does not need to be divided between positive and negative. The reading method is the same as the reading method for measuring DC voltage mentioned above, except that the numbers should refer to the pointer position on the scale line marked with the AC symbol "AC".
