A How to use the universal meter - Check whether the positive and negative poles are correct before using the universal meter, check whether the connecting wires of the red and black test rods are connected to the corresponding color binding posts. The red pin test the positive electrode side of the tested part, while the black pin tests the negative electrode of the tested part. If you don’t know which pole is the positive and negative of the tested part, it is recommended to set the transfer switch to the largest DC voltage, then place the test pin on any one of the tested pole, and then use the other pin at the other pole. If the pointer of the universal meter to the positive direction, then the red pin is connected to the positive pole and the other is the negative pole. Otherwise the red pin and black pin are connect in contrast.
B How to use the universal meter - change from large to small magnification when using; Some universal meters also have a special high-voltage insulating test pen when measuring high voltage. When measuring, be sure to ground the negative pen first, and the other test pen to set the height. Potential. Also note that the resistance and current files cannot be used to determine the voltage. When changing the range, you must change the magnification from large to small. This will not damage the meter.
C How to use the universal meter - Transfer the switch to the high grade after using; Every time after using the universal meter, it is recommended to switch the universal meter to the high grade, which is convenient for the next operation. When measuring the resistance of ohms, select a suitable multiplying power, let the pointer indicate where the scale is thin, so that the measured data will be more accurate.
1. In this case it will be safe, the terminals have an insulated casing and ensure that the copper wires are not exposed to the outside and short-circuit with each other.
2. Check the polarity of the power cord. It is estimated that the switching power cable does not go through the live wire, but the neutral wire. The switch should be connected to the live wire, otherwise there will be shimmer in the light after turned off the switch if the switch go through the neutral wire, meanwhile the switch will not be safe. It is better to take the live wire safely.
3. A. Reading more professional books to improve your knowledge reserves. B Improve your hands-on ability, get more experience from the examples, consult with the old electrician, and learn with humility. C Participates in vocational training, and obtains higher-level skills certificates to enrich your literacy. D exchanges and learns with your peers, takes its essence, drop its dross, learns lessons, and be strict with yourself.