How to use a multimeter to measure 220V AC voltage
Set the range switch to 500V AC. The full scale is 500V, and the reading is according to the scale 1:1. Insert the two pens into the power supply socket, the scale pointed out by the needle is the measured voltage value. When measuring AC voltage, there is no positive or negative difference between the pens.
Multimeter voltage measurement method should firstly align the range switch with the five gears within the range labelled V (test AC voltage to align the AC voltage gear, test DC voltage to align the DC voltage gear). To measure voltage, connect the meter pens in parallel to the circuit under test. Select an appropriate range position according to the approximate value of the circuit under test. The maximum value of each dry cell is 1.5V, so it can be placed in the 5V range gear. At this point in the panel needle full scale reading of 500 should be made 5 to read. That is, 100 times smaller. If the pointer is pointed at the 300 scale, it is read as 3 V. Note that the range switch pointed to the value of the full-scale reading of the pointer on the head of the table, read the table as long as it is converted accordingly, you can read out the real value. In addition to the resistance file, range switch all files are read according to this method. In the actual measurement, when you can not determine the approximate value of the measured voltage, you can switch to the maximum range file, and then reduce the range to the appropriate position. Measurement of DC voltage should pay attention to the positive and negative polarity, if the pen is connected to the opposite, the needle will play back. If you do not know the positive and negative polarity of this circuit, you can put the multimeter range on the maximum file, and try it on the circuit under test very quickly to see how the needle deflects, you can judge the positive and negative polarity.
Notes on the use of multimeter
(1) Before using the multimeter, it should be "mechanically adjusted to zero", i.e., when there is no measured quantity of electricity, the needle of the multimeter should be pointed at the position of zero voltage or zero current.
(2) In the process of using the multimeter, you should not touch the metal part of the pen with your hand, so as to ensure the accuracy of the measurement on the one hand, and ensure the accuracy of the measurement on the other hand.
This can ensure the accuracy of measurement on the one hand, and ensure personal safety on the other hand.
(3) When measuring a certain amount of electricity, you should not change the gear at the same time of measurement, especially when measuring high voltage or high current. Otherwise, the multimeter will be destroyed. If you need to shift gears, you should first disconnect the pen, shift gears and then go back to the measurement.
(4) When using the multimeter, it must be placed horizontally to avoid errors. At the same time, it should also be noted to avoid the influence of external magnetic field on the multimeter.
(5) After the multimeter is used, the changeover switch should be placed in the maximum block of AC voltage. If it is not used for a long time, the battery inside the multimeter should be taken out, so as to avoid the battery corroding other devices inside the meter.
How to use the multimeter
1,Be familiar with the functions of the multimeter before use, and select the correct gear, range and pen jack according to the object to be measured.
2, in the size of the measured data is not clear, should be the first range switch, placed in the maximum value, and then by a large number of range to the small range file to switch, so that the instrument pointer in the full scale of 1/2 above the place can be.
3, the measurement of resistance, after selecting the appropriate multiplier file, the two pens touch so that the pointer in the zero position, such as the pointer deviates from the zero position, you should adjust the "Zero" knob, so that the pointer to zero to ensure that the measurement results are accurate. If you can not zero or digital display meter issued a low-voltage alarm, should be checked in time.
4, in measuring the resistance of a circuit, you must cut off the power supply of the circuit under test, and do not measure with electricity.
5,When using the multimeter for measurement, pay attention to the safety of the person and instrumentation equipment, the test shall not touch the metal part of the meter pen with hands, and do not allow switching the gear switch with electricity to ensure accurate measurement and avoid accidents such as electrocution and burnt instrumentation.
