Based on the analysis of the design principle and internal structure of the truck scale, the reason of the failure of the truck scale in the test period is found. The main reason is that the quality is not high, the aging of the truck scale, the environment and the human factors are analyzed.
Truck scale is closely related to modern automatic control technology, electronic computer and microelectronics technology. Especially in recent years, truck scale has been developed rapidly because of its fast speed, complete function, easy remote transmission and modern management. The truck scale has become the leading product of the weighing industry, and has been widely used in various factories such as mines, ports, grain storage, medicine and bulk items, and has become an important equipment for trade settlement, automatic detection and monitoring.
According to the relevant laws and regulations of the state, the quality supervision department shall, for every six months, conduct a compulsory test on the trade balance of trade settlement. As a result of people's livelihood measurement, quality supervision departments to give full attention to the input of more manpower and resources to prevent the lack of short two, harm the behavior of consumers, so any function of the truck as long as the measurement does not hinder the requirements are given to consider. However, in the repeated cycle of verification and supervision of checks are often found in the car value of the value of ultra-poor, Xiao Bian through the investigation and analysis of a large number of targeted tests, that the value of the vehicle value is caused by the following aspects of tolerance The
First, the quality of truck scale is not high
The design and manufacturing techniques of the truck scale and the material properties selected for the manufacture of the truck scale, the metrological performance and accuracy of the truck scale, the weighing indicator and the weighing area affect the accuracy of the metering device.
At present, the major test positions standing with the truck are mostly domestic truck scale, in different environmental conditions can not guarantee the consistency of its measurement performance.
Second, the truck scale aging
Part of the test station built a long time, truck scale scale life is too long, its performance has been unable to meet the needs of the current work. At the same time, due to the busy business, the daily heavy truck overweight compared with the previous, a substantial increase, and overload the work of the general phenomenon, further exacerbated the scale body and sensor aging, so that the actual life of far Lower than its design life, while the enterprises to save costs, equipment updates are slow, resulting in the use of truck scale measurement performance decline.
Third, the environmental impact
1. Impact of influencing factors on test results
A large number of on-site inspection data show that changes in ambient temperature and humidity, vibration, pressure, etc., will have an impact on the accuracy of the test results, according to JJG555-1996 "non-automatic scale" test procedures requirements, , Which requires that it meet the general measurement requirements and technical requirements, but also need to meet the performance requirements of the impact factor, the impact factors include static temperature, hot and humid and other environmental factors.
The operating temperature range of the truck scale should be in the range of -10-40 ° C for the illustrative markings of the truck scale, and the temperature limits should meet the conditions in Table 1 for special cases.
Electronic components in the temperature and humidity changes under the influence of performance may change, so the specific provisions: Weighing in the upper limit of the temperature range and 85% relative humidity, should meet the measurement requirements. (The upper limit of the truck scale is the maximum value of the selected operating temperature range. For example, if a truck has a specific operating temperature range of -20-30 ° C, the upper limit of the temperature is + 30 ° C).
2. Truck scale measurement performance is not stable
In the field testing often found that the same detection conditions, before and after several significant changes in test data, much more than JJG555-1996 repeated measurements on the specified range of reproducibility, indicating that the truck scale meter due to design and manufacturing technology reasons, Accuracy and stability to be improved; at the same time in the complex, harsh working environment, the truck scale due to prolonged overload operation, wear, aging serious.
In addition, for the dynamic automatic truck scale, road damage, vehicle speed and other external environment on its measurement performance has a great impact on the highway for dynamic vehicle automatic truck scale is particularly evident.