Things to note when using an analog multimeter
In the operation and maintenance of electrical equipment, multimeters are used very frequently. Improper use or carelessness often leads to measurement errors or instrument damage accidents. Therefore, you must learn to use a multimeter and develop good habits of calmness, caution, and correct operation.
When using a multimeter, pay attention to the following points:
1. Read the product manual carefully before use, fully understand the performance of the multimeter, correctly understand the meanings of various symbols and letters on the dial and the reading of each scale, understand and be familiar with the functions and usage of transfer switches and other components.
2. The multimeter should be placed horizontally, away from strong magnetic field areas (for example, keep a certain distance from generators, motors, busbars, etc.), keep it clean, dry, and away from vibration, heat, and moisture.
3. Before measurement, the transfer switch should be moved to the appropriate position according to the item to be measured (such as voltage or resistance, etc.); check whether the pointer is pointing at the mechanical zero position. If it is not at the zero position, it should be adjusted to the zero position.
4. The wiring should be correct. When inserting the test pen into the meter hole, the plug of the red test pen should be inserted into the "+" hole, and the plug of the black test pen should be inserted into the "-" hole; when holding the test pen, fingers must not touch the metal part of the test pen to ensure personal safety. and measurements are accurate. .
5. When selecting the measuring range, try to deflect the pointer to approximately 2/3 of the full scale of the scale. If it cannot be estimated in advance that the measured value is too small, you can gradually reduce it from the maximum range to the appropriate range during measurement; when adjusting the amount, do not use too much force to avoid hitting other ranges and damaging the meter; pick it up every time When the test pen is ready to measure, be sure to calibrate the measurement items again and check whether the measuring range is set correctly.
6. During testing, the test leads should be in reliable contact with the part being measured; if there is oxide film, dirt, soldering oil, paint, etc. on the conductor surface of the test part, they should be removed to avoid measurement errors caused by poor contact.
7. When the switch is turned to the current position, the two test leads should be connected across the power supply to prevent the multimeter from burning; after each measurement, the transfer switch should be placed in the neutral position or the highest voltage position, and the switch should not be placed in the electrical block to avoid The two pens are short-circuited by other metals and the battery in the meter is drained, or the meter is burned due to misconnection.
8. When measuring, do not turn the wrong selector switch or plug into the wrong socket. From: Home of Electrical Technology
9. When measuring, it is necessary to know which scale the reading should be based on the selected measurement item and range, and understand what value a small grid on the scale represents. When reading, your eyes should be perpendicular to the surface, not to the left or right. Otherwise, the readings will have errors. Multimeters with higher precision have a curved reflector under the scale on the surface. When the pointer coincides with the shadow in the mirror, the reading is most accurate. Under normal circumstances, in addition to reading the integer value, one decimal place should be read based on the estimated position of the pointer.
10. When changing the measurement range, additionally adjust the zero point and then measure; once the battery in the meter is over-consumed, replace the battery in time.
