Nine precautions for overhauling instruments and meters

In the maintenance of instruments and meters, we must first understand the basic principles of instruments and meters, and master the knowledge and skills related to electronics, and we should prepare all the instrument and meter manuals, drawings and other technical materials. In addition, we should develop a good Work quality, thereby improving efficiency and reducing errors in the maintenance of instruments and meters. 1. When using a multimeter to ohmic block, remember not to perform instrument maintenance work. First, you should understand the basic principles of instruments and meters, and master the knowledge and skills related to electronics, and prepare all instrument manuals, drawings and other technologies. In addition, a good work quality should be cultivated to improve efficiency and reduce errors in the maintenance of instruments and meters.　　1. When using a multimeter to ohmic block, remember not to perform live measurement.　　　　　 2. When using a logic pen or oscilloscope to detect signals, be careful not to make the probe touch the two measurement pins at the same time, because the essence of this situation is to form a short circuit when the power is turned on.　　　　　　 3. When detecting the filter capacitor in the power supply, you should first short-circuit the positive and negative electrodes of the electrolytic capacitor, and do not use the test lead wire to replace the lead to discharge the capacitor when it is short-circuited, because it is easy to burn the core wire. You can take a 220V, 60-100W lamp with a lamp cap and connect it to both ends of the capacitor. The bulb will flash at the moment of discharge.　　　　　　 4. When troubleshooting the instrument in a humid environment, it is necessary for the printed circuit to use a multimeter to test whether the points are unobstructed, because the main fault in this case is the corrosion of the copper foil. 5. When inspecting and repairing the internal circuit of the instrument, if the contact points of the installed components and the circuit board are coated with insulating varnish, ordinary hand stitches can be welded to the test pen of the multimeter when measuring the parameters of each point, so as to pierce the paint layer and directly measure each point. There is no need to peel off the paint over a large area.　　　　　 6. Do not plug or unplug various control boards and plugs with power on. Because when the power is on, plugging and unplugging the control board will generate a strong induced electromotive force. At this time, the instantaneous counterattack voltage is very high, which can easily damage the corresponding control board and plug.　　　　　 7. Do not knock or touch blindly during maintenance, so as not to enlarge the fault, the more the repair, the worse.　　　　　 8. When disassembling or adjusting the meter, the original position should be recorded in order to restore it.　　　　　 9. When repairing precision instruments and meters, if you accidentally bounce small parts off, you should first judge the place where they might fly. Don't look for it, or turn it around. You can use magnet scanning and sight scanning methods to search. In short, in the maintenance of instruments and meters, we should first understand the basic principles of instruments and meters, and master the knowledge and skills related to electronics, and we should prepare all instrument manuals, drawings and other technical materials. In addition, we should develop a Good work quality, thereby improving efficiency and reducing errors in the maintenance of instruments and meters.