I. Overview: The load cell, load cell, and weighing instrument are the three fundamental components of electronic weighing instruments. Among them, the scientific and rational structure of the load cell is an important guarantee for the accuracy, stability, and reliability of electronic weighing instruments. Today, as the electronic weighing instrument market becomes increasingly internationalized, the improvement and innovation of the structure of electronic weighing instruments must be guided by the needs of users and market competition, and be strongly driven by new technologies, new materials and new processes. Since the beginning of the 21st century, with the advancement of science and technology and the improvement of the automation and intelligence levels of industrial processes, various industries have put forward many new requirements for the structure, function and performance of the electronic weighing instruments they use. Among them, the most important requirements for the load-bearing devices are miniaturization, lightweight, modularization and integration. If the design of electronic weighing instruments still follows the traditional assembly structure of components such as load-bearing devices, load cells, load-bearing and force-transmitting components, and positioning and limit devices, not only will it fail to meet the new demands of users, but its own development will also become increasingly difficult. Based on the existing structure of the carrier, in order to enhance technical performance and meet some new requirements of users, even minor improvements can only be achieved at a relatively high cost. As German weighing instrument experts commented in the 1990s, "The structural design of this component-assembled load-bearing device has almost reached its end." Because the structure of the component assembly type load-bearing generally has disadvantages such as being large and heavy, having many components, numerous moving links, long installation and commissioning time, poor stability and reliability, low production efficiency and high cost. Therefore, German weighing instrument experts have proposed: "When designing the structure of the load-bearing device, it is necessary to break away from the constraints of traditional structures as much as possible and boldly seek another development direction, that is, to develop in the direction of reducing size, reducing components, saving space, which is conducive to achieving optimal production, improving efficiency, and reducing costs." Based on this understanding, some domestic and foreign electronic weighing instrument manufacturing companies have conducted extensive research on the structure of load-bearing devices. Their common research and development direction and innovation point is to transform the component assembly load-bearing device structure into modular, partially integrated and integrated load-bearing device structures. It has successively developed modular electronic truck scales and small module assembly electronic truck scales that are convenient for transportation. Partially integrated load-bearing, force transmission, positioning and limit device integrated electronic truck scales and electronic hanging scales; Integrated weighing rail dynamic electronic rail scale, integrated shearing and bending plate type dynamic highway vehicle axle load scale, integrated electronic weighing ring; Hollow closed section thin-walled steel structure electronic weighing beam, "bamboo row" type thin-walled steel structure electronic platform scale; Special-purpose load-bearing devices such as extendable electronic scales and split-type rolling round bundle paper electronic scales, etc. Ii. Modular Electronic Weighing Instruments 1 As early as the 1990s, Mettler-Toledo (Changzhou) Weighing Equipment System Co., Ltd. was the first in China to achieve the design and production of modular electronic truck scales. The designers applied the orthotropic bridge design theory to the modular bearing design and made appropriate simplivities. They combined the longitudinal beam and the main beam into one, forming a closed structure of "U" shaped steel. Then, they simplified the bottom beam into end plates, on which the lap connection between modules and the transition support of the load cell were completed. The entire load-bearing module is composed of only "U" -shaped steel, panels and end plates. The so-called modular load-bearing device refers to several standard modular load-bearing devices designed and manufactured based on the length and rated load capacity of heavy-duty trucks and trailers. According to the user's size requirements for the load-bearing device, two or more modules can be randomly connected to form electronic truck scales of various specifications. For instance, based on the length of heavy-duty trucks ≤12m, the length of tractors and semi-trailers ≤16m, and the length of truck trailers ≤20m, the unit length series of modular load-bearing units are selected as 5m, 6m and 7m, and the preferred width series are 3m and 3.3m. Each series of single, two-piece, three-piece and four-piece modules of different widths and lengths can be combined into 22 different size specifications of load-bearing devices ranging from 5 to 28 meters in length. Select a dozen or so commonly used load-bearing device lengths from them as the preferred standard series. This modular electronic truck scale not only enhances the universality and interchangeability of the product, but also significantly improves production efficiency and product quality, making it particularly suitable for large-scale and automated production.