Weighing and metering equipment plays a key role in the transportation of goods. In recent years, electronic truck scales have been widely used and widely used. The advantage of the platform is accurate and fast, which is favored by many technicians. This paper mainly discusses and analyzes the relevant content of the verification of the weighbridge and the on-site troubleshooting.

Foreword

The scale is susceptible to interference and interference from many external factors during the specific use. Once such a detection tool fails, it will seriously affect its normal use and directly affect the accuracy of the test results. The paper describes several common problems in the verification of land scales and proposes specific solutions.

1. Analysis of common problems in the verification of floor scales

1.1 The problem of the body itself

The weighing platform is an important component of the weighbridge. This component is mainly used to carry heavy loads. In the specific use of the ground scale for inspection, it is necessary to check the bottom surface of the naked eye symmetry body, the weighing body itself, and the guard frame gap at both ends of the weighing body to see if there is a significant problem. There are several common types of weighing problems: whether there is any debris stuck in the body, whether there is a connection between the weighing bodies that is not compact enough, and whether the sensor of the weighing body is displaced.

Like and so on.

1.2 Sensor problem

The sensor is an important component between the foundation and the platform. The main function of the component is to convert the weight of the cargo into a corresponding electrical signal. Damage to the sensor may be caused by a serious overweight of the goods, or it may be because the sensor is damaged due to the lack of quality of the goods, resulting in poor insulation, zero drift or signal line looseness.

1.3 The detection technology is not up to standard, and the obtained test results have large errors.

The accuracy of the eccentric test results determines the accuracy of the final test results. However, in actual measurement, due to different specifications of the weight specifications or poor standard deviation, it is easy to cause the resulting test results to deviate from the actual phase. This inaccurate partial load test can satisfy the verification of the device. Actual requirements have a direct impact.

1.4 meter problem

The weighbridge display meter function measures the current and voltage changes of the sensor for accurate weight measurement. If you want to find the exact location of the scale instrument failure, you can usually use the simulator, or you can use an alternative method to diagnose the instrument failure. When the alternative method is used for the measurement, the repeatability can be checked by repeatedly loading it three times on the carrier with a close substitute of one-half of the maximum weighing.

1.5 The detection conditions are limited, and the measurement infrastructure equipment is imperfect.

In China, there are still insufficient capital investment in the measurement infrastructure construction, which leads to the limitation of the verification conditions of the metrological verification units in some areas, and the phenomenon of insufficient standard equipment is generally unsatisfactory, which is not conducive to meeting the needs of real work. In combination with the current verification department at the county (city, district) level, the legal code weight of the verification equipment is usually < 50t, but in practice, the verification operation of the > 50t floor scale frequently occurs, which is seriously inconsistent with the current actual demand. . At the same time, safely transporting standard weights is a very important and difficult problem. Safe transport standard weights not only have to bear high transportation costs, but also add to the cost of the investment. It is important to ensure the tightness of the standard weight transport and to avoid the occurrence of safety accidents caused by bumps during transportation.

1.6 Offset correction problem of eccentric load

Regarding the offset correction problem of the eccentric load, different measurement and correction methods can be adopted in combination with the size of the weighbridge. In general, most of the weighbridges are corrected by using a forklift to transport a large yoke pressure angle difference. If it rises to the theoretical level, the specific operation is as follows: 100t, the three-section is that the pressure angle of the eight sensors should be 15t (100t+(8-1)=15t), and the position of the added weight should be as shown in Figure 1. Show the partial load test.

When testing a certain focus, the closer the test weight is placed to the sensor, the better the position of the support.

In addition, due to the existence of various types of floor scale devices on the market, different manufacturers often adopt different calibration procedures if they have an eccentric load problem. For the electronic truck scale of the analog sensor, the deviation of the eccentric load can usually be solved by the measures of the potentiometer. For electronic vehicle scale digital sensors, the eccentricity deviation can be corrected directly from the instrument head. For example, the quality measurement and inspection of Shantou City uses a static electronic truck scale. In the measurement performance and periodic inspection of this equipment, the following standards are generally adopted: the total mass of the vehicle of this check vehicle is 16 tons. The following two specifications are available, one of which has a weight of 1t and the other has a weight of 500kg. In the actual verification operation, if the total weight of the truck scale is within the weight range of the standard weight, basic operation steps can be used for verification.

2. On-site troubleshooting measures for the weighbridge

2.1 System troubleshooting of each component before use

Before the test, you should first communicate closely with the pounder to fully understand the daily maintenance and usage of the weighbridge, and then work in a targeted manner. Then, the level of the single base plate can be detected by the level meter, and the level difference between the base plates can be detected by the level meter. The hitting sound can be taken by the tapping of the base board to judge the enrichment condition under the device and whether there is no air pocket. . At the same time, the rationality of the limit gap should be checked, and the gap around the symmetry table should be cleaned to prevent the gap from being caught by the foreign object. At the same time, the bottom of the symmetrical table should be cleaned to prevent the foreign matter such as garbage from supporting the body. . In addition, the inspection work of the sensor head, the steel ball and other connecting parts of the weighing platform should be carried out to eliminate the problems such as loose parts and damage of the parts, and the method of applying butter to the rust can be protected.

2.2 Do a good job of routine maintenance of weighing instruments

Generally, the temperature of the working environment of the meter should be kept at _10 steep 45 ,, and the air humidity should not exceed 90%. The instrument should use a dedicated regulated power supply to improve its stability and ensure its normal operation. If the meter has not been used for a long time, it should be checked for power before use again to ensure it is safe to use. Once the instrument has failed during use, it should be powered off immediately, and then assigned maintenance personnel to timely repair, try to avoid unauthorized removal, affecting its normal use. 2.3 Handling of the instrument after the instrument is turned on or not resetting after loading and unloading If the zeroing range setting is too small, it will not reset to zero, and it is usually necessary to reset the meter. At the same time, it is necessary to check whether the body is stuck by foreign matter, and the foreign matter in the body should be cleaned up in time to ensure the flexibility of the weighing body. Some are caused by the zero drift of the sensor. In this case, the relevant technicians are required to inspect the sensor in detail, and whether the output signal of each sensor is in the normal range without weighing any heavy objects. Test If the sensor zero drift is not very serious, just calibrate the meter. If the drift is serious, the sensor needs to be replaced.

2.4 shows the treatment measures with large weight error

At the time of the inspection, there are often cases where the error of the large and large tonnage detection results is relatively large. In order to improve the accuracy of the verification, the following measures can be taken. For errors in small tonnage tests, multiple iterations can usually be performed for processing. The large tonnage test is prone to the situation where the stopper is stuck, or because there is a foreign object between the shift and the base, the deformation of the scale during the detection causes the sensor to be linearly inferior. Check the method to confirm the fault, then take appropriate measures to ensure that the relevant verification work can be carried out smoothly.

2.5 scale load is not linear

In the specific check, whether the increase or decrease of the weight should be based on the weight of the weight increase or decrease, and the value displayed by the meter should also increase or decrease linearly. If this is not the case, check the scale body to see if it is stuck by foreign objects or if the limit clearance of the limit device is normal. If there is any foreign matter, the circumference of the scale body should be cleaned, and the lateral limit clearance of the limit device is 2mm, and the longitudinal limit gap is 3mm. If no problems have been found before the inspection, it is possible to initially determine that there is a problem with the sensor.

Conclusion

When weighing with the detection device of the weighbridge, there are often many failure problems. In troubleshooting, you should adhere to the principle of easy to difficult to check one by one. Therefore, this matter generally requires the positioning, analysis and resolution of these major steps. At the same time, relevant technicians are required to analyze and summarize the common problems in the actual verification, and propose solutions to these problems. By summarizing the problem and proposing solutions, it not only helps to ensure the reliability and accuracy of the weighbridge test, but also has some reference for the current field of scale verification.