Simple instrumentation fault determination

Instrumentation is common in our production applications, so its maintenance is also an integral part of it. Today's instrument and meter world network Xiao Bian will tell you about the fastest and most convenient method for all staff to quickly determine the fault of the instrument.

First, the observation method. Uses sight, smell, touch. In some cases, the damaged components will discolor, blistering, or burn spots; burned devices will produce some special odors; short-circuited chips will become hot; visible or unwelded areas can also be observed with the naked eye. . This method is more suitable for experienced staff.

Second, the elimination method. The method of determining the cause of the fault is determined by inserting and removing some plug-in boards and devices in the machine. When the instrument returns to normal after removing a certain board or device, it indicates that the failure occurred.

Third, tap the hand pressure method. When we encounter a situation in which the instrument is running, it is best that we use a percussion hand pressure method. The so-called "knocking" is to lightly hit the board or component with a small rubber hoe or other knocker to see if it will cause an error or stop failure. The so-called "hand pressure" is when the fault occurs, after the power is turned off, the plugged parts and the plug and the base are pressed again by hand, and if the power supply is turned on, it will eliminate the fault. If it is found that when the cabinet is normal and the beat is not normal, it is better to re-insert all the joints and try again. If you are unsuccessful, you have to find another solution.

Fourth, the comparison method. Two instruments of the same type are required and one is in normal operation. Use this method also has the necessary equipment, for example, multimeter, oscilloscope and so on. According to the nature of comparison, there are voltage comparison, waveform comparison, static impedance comparison, output comparison, and current comparison.

Fifth, the replacement method. Two instruments of the same type or enough spare parts are required. Replace a good spare with the same component on the faulty machine and see if the fault is eliminated.

Sixth, parallel law. Place a good IC chip on the chip to be inspected, or connect good components (resistance capacitors, diodes, transistors, etc.) in parallel with the components to be inspected to maintain good contact if the fault is caused by an open circuit inside the device or For reasons such as poor contact, this method can be ruled out.