Abstract: At present, the rapid development of our market economy has made the trade more and more prosperous. In order to reflect fairness and reasonableness, people continuously explore various measurement methods. Automatic weighing instruments are widely recognized and widely used devices. The automatic weighing instrument mainly refers to the weighing that can automatically calculate the result in the weighing process, and does not need to be operated by manpower. The measurement is accurate and the error rate is low. Then, in order to ensure the accuracy of the automatic weighing instrument, it needs to be checked regularly, which makes the verification work more and more important. The article mainly discusses and analyzes the importance of weighing instruments and comprehensively describes the verification methods and measures used by automatic weighing instruments.
In the long course of human development, trade has a long history. In all kinds of metering equipment, weighing instruments are used more widely, and they have experienced a long history and evolution. Global economic integration and the rapid development of modern networks have enabled the global economy to enter a new era of information, digitalization, and intelligence. Weighing instruments are the most commonly used important measuring instruments in the field of contemporary commerce and trade. The accuracy of their measurement has a direct impact on business relations and trade fairness. Regardless of which country, it attaches great importance to measuring instruments.
1 The importance of weighing instruments
Weighing apparatus is a kind of special appliance. Our country has stricter control over it and implements the permit entry system. Weighing devices are subject to verification from the start of the shipment, and after they are in the hands of users, they must go through processes such as storage, transportation, handling, and installation. A series of activities led to inaccurate measurement of the instrument. Some instruments were not put into use, resulting in damage and loose parts. In some units, after being distributed to the users, the appliances are not effectively corrected, and those who use the appliances are not necessarily professionals. Some minor problems cannot be discovered in time. This can cause errors and lead to errors in measurement. Therefore, before the instrument is put into use, it is necessary to conduct a comprehensive verification. The professional and technical personnel shall perform the verification on the spot and use the relevant metrological verification procedures as basis. If the problem is found, the problem needs to be resolved in time. When all the verifications are completed, After that, that is to say, after the verification result meets the measurement requirements of the weighing instrument and the requirements specified in other verification procedures, the measurement instrument verification cycle time can be marked. At this time, it can be put into use safely.
With the development of modern technology, more and more kinds of weighing instruments are manufactured, and different models have different structures and principles. Differentiated instruments require different verification methods. Then, when the verification cycle is established before it is put into use, To fully and comprehensively consider these influencing factors, the verification cycle is subject to conditions, especially the performance of the instrument itself, the use of the environment, air conditions, accuracy requirements, and routine maintenance, all affect the setting of the verification cycle. Only under the principle of ensuring that the use of scales exceeds tolerances should be minimized, the length of the verification cycle and the cost of annual inspections should be used as criteria, so as to scientifically and reasonably determine the verification cycle that meets the performance of the appliance itself.
Weighing devices in China are within the scope of mandatory verification, because such special measuring instruments play a large role. If problems occur, they will have a greater impact. We must follow two criteria when determining the weighing device verification cycle. One is to ensure that the weighing instrument has a high accuracy of the measurement effect within a valid period of the verification, and has a good qualification rate; the other is to focus on saving, no unnecessary waste, and reduce the input of material and manpower. If we say that the weighing instrument verification cycle is set unreasonably, if it is too long, there will be a large number of weighing instruments that fail to pass the verification within the validity period. If it is too short, it will lead to unnecessary manpower and material waste, which will affect the production of weighing instruments or users. Life has increased the user's trouble.
2 automatic weighing method
2.1 Static verification method
The verification method for non-automatic weighing instruments is mature and widely popularized and applied. The verification methods for automatic weighing instruments are basically the same as non-automatic instruments. Under normal circumstances, it is necessary to add a certain weight to the weighing instrument, and the weight carrier is checked by the weight. The validity of the method is determined by the speed and value of the weighing value transmission process. The standard instrument used in this method is the weight. The internationally accepted standard is the M1 weight, that is, the weight of the mid-weight can be used to effectively complete the automatic verification of the automatic weighing instrument to ensure that its measurement uncertainty is less than 1/1 of the maximum allowable error of the instrument to be inspected. 3 standard regulations.
2.2 Dynamic Verification Method
Dynamic verification is the opposite of static verification. That is to say, when the instrument is working, or if an analog scale weighing test is assumed, the verification process is completed through the analysis of this process. Dynamic verification can not add the standard weight to the actual operation of the instrument, can not determine the final value, can not get the error rate, so that the dynamic verification needs to use a special way to verify, the resulting automatic weighing instrument dynamic error is Final Results. We use the method of load assessment and expect to weigh the material as a load standard. In this method, the weighing material (ie, load) that has been tested by the automatic weighing instrument is taken down and measured with another instrument. The other instrument should be a higher-accuracy instrument. At this time, a set of values â€‹â€‹will be obtained. The set of values â€‹â€‹can be either agreed values â€‹â€‹or actual values. We can calculate the difference between the two by using the weighing data displayed on the static weighing instrument. The value of the static weighing instrument is the load. The agreed truth value, then the error formed by the difference between the value of the automatic weighing instrument being examined and that of the static weighing instrument, indicates whether the instrument being tested is accurate.
2.3 Separation test
We can effectively control the weighing instrument through separation and obtain the verification result through dynamic verification. This method is the separation verification method. Some automatic weighing instruments are equipped with an identification of the true value of the specified load at the factory. This indicating device is professionally designed and can be compared to determine whether or not it is accurate. The device can complete the static control weighing instrument, so that the weighing instrument is more stable in use. This is what is commonly referred to as an integrated control weighing instrument. The integrated control weighing instrument and the checked automatic weighing instrument are integrated together to form a closely related and indivisible whole. Under normal circumstances, automatic weighing instruments with small scales have the characteristics of lighter load, less material, and easier handling. The majority of such instruments use the method of separation and verification. As a verification method, the separation verification method has formed a complete system in the long-term practice. This method is divided into online verification and offline verification. The online verification is mainly controlled by an electronic hopper scale; offline verification is Use electronic truck scales or track scales as scale controls. Automatic weighing instruments perform dynamic weighing on a preloaded discrete load or a discrete single load and classify or test it. When performing the test, select those loads that are exactly sized and of reliable quality as simulated loads. The dynamic vehicle scale is the weighing of the running vehicle to determine the total vehicle mass and shaft load. A numerical value can be selected. This value can be the truth value pre-agreed, the following integrated verification method is used for the verification of the automobile scale, and the dynamic shaft balance verification uses the separation verification.
2.4 Integrated verification method
The use of integrated control instruments to perform dynamic verification is an integrated verification method. There are some large-scale automatic weighing instruments whose weighing tonnage exceeds the normal, and this method is required. Such an instrument has the characteristics of heavy load, large amount of materials, and difficult transportation. Therefore, this method is more suitable for the verification of large-scale appliances. Quantitative automatic weighing instruments can divide bulk materials into different packages through automatic weighing. When testing, the pre-weighed materials can be used as a standard, which can be performed by static weighing method or by using separation testing. The law comes to completion, and at the same time, the integration verification method is also more applicable. It is impossible to form an automatic weighing instrument that can continuously accumulate, and it is possible to disperse a pile of materials into different equal parts, and to form the sum of the final total amount through constant load reservation. Regardless of whether it is a separation test method or an integrated test method, it is necessary to meet the requirement that the measurement uncertainty is less than 1/3 of the allowable error of the automatic weighing instrument to be tested during operation. If this rule is followed, it is considered as unqualified. It is worth noting that during the verification process, it must be ensured that the distance and the climate do not affect the results. At the same time, some materials need to be kept strictly and no road loss or damage can occur. Otherwise, the quality of the load will be affected.
3 Strengthen Weighing Record Management
The verification record records the values â€‹â€‹and problems of different verification periods. This record needs to be kept, because the original instrument of the weighing instrument can explain what happened in its own cycle, and it is an important technical reference material. Without such data, it cannot be conclusively concluded. Can not issue a certificate. Weighing verification records management is a rigorous job, not only representing the business management capabilities of the certification body, but also the image of the certification body. If there is a problem, it will affect the credibility of the certification body. Through the need to establish professional personnel and departments to strictly manage the verification records, it is not possible to lose the damage and ensure the realization of the statutory effect. A copy of the appliance verification certificate shall be promptly affixed to the blank area of â€‹â€‹the record book, and be able to correspond to the certificate of conformity for easy access to and understanding of the appliance information.
In summary, weighing instruments are the most important measuring instruments in the business field today. The fairness and fairness directly to the transaction, especially the fairness in the settlement, we can only strengthen the business ability and management level in order to work in the measurement verification of weighing instruments. Safeguard the legitimate rights and interests of the country and consumers.
 GUO Shuyi, GAO Hui, FAN Xiping. Calibration instrument for scales[J]. Enterprise Standardization, 2007(7).
 Yan Xuelin. Analysis of calibration and calibration of electronic balance [J]. Quality and Technical Supervision, 2011(6).
Author: Zhao Hongyan Source: technological innovation and application of 2016 7
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