Medical laboratory equipment failure of the law, types and causes of a man-made laws faulty equipment failure statistics in general rule is: the early use of the instrument, the higher the possibility of failure, which was mainly due to the quality of components poor, the aging process is not strict screening, assembly defects in workmanship, poorly designed, and the operation of human errors and other factors, therefore, the lower the reliability of this period or that the failure rate is higher. This person is called the period of early failure of the instrument. After a period of operation, the instrument's components, organizations through the whole rationale for the adjustment, have been gradually adapt to the normal operating state, the instrument used to enter the stable period, the incidence of failure is low, and the majority are generally accidental failures. The instrument is in top working condition, this period is called the effective use period. After a long run later, with the various components, especially vulnerable components, structure, wear, wear and tear gradual increase in the failure rate of the instrument has gradually increased, the loss of this period for the instrument failure period. Early general instrument malfunction of electronic components, while the loss is more common in mechanical failure of components or optical components. Second, the failure types and causes of failures of equipment failures and accidental failures inevitability. Inevitability of failure is a variety of components, parts, after very long use, performance and changes in the structure, resulting in the instrument can not perform normal work, such as component aging, deterioration, potentiometers wear. Accidental failure refers to a variety of components, structures, etc. due to the influence of external conditions, the nature of a sudden change, leaving the instrument can not perform normal work, such as an AC voltage is too high, the instrument by the shock. The main cause of the failure produced detailed analysis is as follows: 1, human-induced failures such failure is caused due to improper operation, and more generally on the use of the program by the operator caused by inexperienced or do not pay attention. Such failures lead instrument light does not work, weight may damage the instrument. Thus, in operation prior to use, you must familiarize themselves with user manual for the correct use of the procedure, act prudently in order to reduce the generation of such failures. 2, equipment failure caused by quality defects ⑴ components caused by the failure of poor quality: such failures due to poor quality of components caused by itself, the same type of component failures with a certain regularity. Troubleshooting common components as shown in Table 11-1. Table 11-1 Common Component Fault table name gradually formed a sudden failure of the optical element failures caused by poor environmental mildew damage so severe vibration, carelessness contaminated photoelectric conversion element easy to aging, poor performance, noise increases work by the glare, excessive damage photocurrent optical coupling devices emitting diodes burn rare mechanical parts using the process of gradually wear down due to precision assembly fixed a bad connection, a sudden failure of structural carbon film resistors ----- ------------- carbon layer due to burn and break the spiral combined resistance drift due to temperature changes caused by the resistance wire wound resistors rare due to resistance caused by contact with the wound sealing off intermittently change the resistance around line burned out and sliding contact with the potentiometer circuit varistor poor contact between the rare due to wear and sometimes no capacitor insulation completely damaged insulation breakdown (short circuit), the wire out of gold metal foil (open circuit) electrolytic capacitor capacity decreased, the leakage large leakage current is increased, resulting in overheating and rabbit escaping gas, blast -------------------- inductor current is too large due to blown diode ------ --------------- burned due to excessive current transistor characteristic parameters change gradually leaving the base current operating point drift too large to burn, the operating voltage is too high and long-term breakdown Manifold use, performance deteriorates and burn excessive current, voltage, reverse polarity, overvoltage breakdown display aging, deterioration of display quality caused by the irrational rare set ⑵ failure: this failure can sometimes result in the components frequently damaged, sometimes you can make the decline in performance of the instrument does not work. Such failure is more common in new products. ⑶ with craft inadvertent failure: These failures are mostly due to cold solder joint during assembly, connector contacts as well as a variety of causes bad touch line, short, break, loose parts produced. 3, long-term use of such failures and faults related component life, caused due to various components of aging, so is the inevitability of failure. Seen from Table 11-1, most devices after prolonged use, will fail, such as optoelectronic devices, membrane electrode aging, monitor aging, gradual wear of mechanical parts, ventilation through the liquid pipe aging and so on. The service life of components vary greatly, so make the instrument can be long-term work, in addition to the vulnerable components to strengthen the maintenance, the timely replacement of these components are also regarded as a positive means. 4, external causes of equipment failure ambient conditions are not met, is often the main cause equipment failure. General environmental conditions refer to the mains voltage, temperature, humidity, electric field, magnetic, vibration and other factors.