Instrument failures and troubleshooting methods \Preventive measures
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What malfunction occurred with the instruments today, and how was it dealt with? Also, how can we prevent similar problems from happening in the future? Please share your thoughts on this topic: http://bbs.hcbbs.com/thread-380635-1-1.html. This post was last edited by Chifeng on 2009-2-3 at 10:11
Experience in the maintenance of measuring instruments: Measuring instruments generally consist of primary components, connection wires (or conduits), and secondary instruments. The fault symptoms are reflected in the secondary instruments, but the cause may not lie in those instruments; it could be in the primary components or the connection wires. Therefore, it is first necessary to determine whether the cause of the fault is internal to the instruments or external to them. Even if the cause of the fault lies in the instrument itself, it may be the result of a combination of various factors; therefore, a step-by-step inspection method is often employed: the entire device is divided into several sections based on its structure and the principles of its circuit operation, after which systematic inspections, tests, and evaluations are carried out to identify the sections that are not related to the fault. This process helps to narrow down the range of possible fault locations until the actual fault point is found. 1. Determine whether the fault point is within the table or outside it. Remove the thermocouple compensation wire from the input terminal, and use a potentiometer to input a test signal for determination. The simplest practical method is to short-circuit the input terminals with a wire; if the gauge indicates the room temperature (for gauges with zero at the starting point), it means the gauge is functioning properly, and the fault lies outside the gauge. 2. Determine whether the fault is in the electrical wiring part of the table or in some other location. At this point, continue to short-circuit the instrument’s input terminals in order to check the internal wiring: 1) Gently pull each connecting wire by hand to check for any signs of looseness, broken wires, or short circuits ； 2) Check whether the positions of each switch lever are correct and whether the contacts of each plug socket are in good condition ； 3) Turn the amplifier sensitivity to maximum and check whether the instrument can operate ； 4) Check the instruments to determine if there are any faults in the transmission system, and whether the sliding contacts have come loose