The classification of weighing products in Chinese history was based on the structure and usage method of the scales, and was divided into three categories: pole scales, mechanical scales, and electronic scales.

（1） Pole scales have a long history and a huge market in China. Weighing rods include bone rods, wooden rods, and metal rods (copper rods, aluminum rods); There are stone weights and metal weights for weighing scales; There are two lifting ropes and three lifting ropes. The evolution of measurement units evolved from the use of zhu and liang during the Xia and Shang dynasties to zhu, liang, jin, jun, and shi during the Zhou dynasty (24 zhu is one or two, 16 liang is one jin, 30 jin is one jin, and 40 jin is one shi). According to ancient books, a total of sixteen stars were recorded in ancient times, including the Big Dipper, the Southern Dipper, the Six Stars, and the Three Stars of Fortune, Fortune, and Longevity. Sixteen star flowers were engraved on the weighing rod, hence the name "Sixteen Two System Scale", which was used until the early days of liberation; In the 1950s, it was changed to a ten liang system, where ten liang was equivalent to one catty and two catties were equivalent to one kilogram. Due to its simple production and easy portability, pole scales are widely used. In the 1980s, the annual output of pole scales in China reached tens of millions; However, the inconvenient operation, slow measurement speed, and poor accuracy of the pole scale are its fatal defects. With the increasing prosperity of the market, this defect has caused greater harm to market development and people's lives. Its negative impact has far exceeded the scope of being short of weight. According to strong feedback from various sectors of society, the State Administration for Technical Supervision and the State Administration for Industry and Commerce jointly issued the "Notice on Restricting the Use of Pole Scales in Public Trade" on September 23, 1994. The position of pole scales was gradually replaced by self display scales (electronic scales, spring dial scales, etc.), indicating that the pole scales that had been used for thousands of years would disappear from people's daily lives; However, as an important symbol in the history of Chinese civilization, its glorious imprint will forever be recorded in the annals of history.

（2） Mechanical scale refers to a general term for weighing instruments with mechanical structures as the fulcrum, including scales, cutting scales, platform scales, spring scales, as well as large and specialized industrial scales.

(1) Balance: Various equal arm levers with a weighing fulcrum in the middle, including balance and tray balance (as well as unequal arm tray balance).

(2) Weighing scale: a lever type mechanical scale used for weighing up to 50 kilograms (excluding 50 kilograms).

(3) Platform scale: a lever type mechanical scale used for weighing between 50 kilograms and 1000 kilograms.

(4) Spring scale: a scale that uses spring tension to calculate load, with single-sided display and double-sided display.

(5) Large mechanical scales and various specialized scales, including ground scales, ground scales, track scales (divided into light rail and heavy rail), hopper scales, belt scales, packaging scales, hanging scales, as well as steel scales, livestock scales, sugarcane scales, grain sales scales, liquid quantitative scales, weighing trucks, etc; Measuring instruments used only for a single industry or process line are called specialized scales, such as postal scales, cigarette scales, etc.

The processing methods of mechanical weighing instruments are easy to master, with low manufacturing costs and sales prices, and a wide range of applications. Therefore, they still dominate the commercial weighing instrument market in China (accounting for more than 90% of production), and also occupy a considerable proportion in industrial weighing instruments. However, due to limitations in design, processing, and debugging methods, mechanical weighing instruments are bulky in size, and their accuracy, weighing precision, and measurement speed are all restricted to a certain extent. Therefore, they have gradually been replaced by high-performance electronic products, and their market is gradually shrinking, with obvious excess processing capacity.

（3） The weight of items carried on the pedestal, tray, and hook of an electronic scale is balanced by the creep reaction of sensors, and the scale displayed by instrument numbers is an electronic scale.

Electronic scales integrate machines, electronics, and instruments, with features such as multifunctionality, high precision, fast and dynamic measurement, stability, and reliability, representing the direction of the development of weighing products. At present, the ten major categories of weighing instruments listed in China's product standards (including table scales, platform scales, above ground scales, mid ground scales, hanging scales, belt scales, hopper scales, inspection scales, track scales, and special scales) have all been digitized. According to recent statistics, electronic products account for about two-thirds of industrial scales (based on sales volume). The measurement range of technically mature static scales can range from 1 μ g to 800 tons. Some non automatic scales (such as electronic price scales, electronic platform scales, electronic ground scales, electronic belt scales, electronic hanging scales, and electronic track scales) have reached the international level in the early 1990s, and some products have reached the level of the mid-1990s; Due to the rapid development of electronic technology in the past decade, the processing capacity of commercial weighing instruments has grown rapidly, product costs have been significantly reduced, and the market has steadily developed. Nowadays, electronic weighing technology has been increasingly applied in industrial production process control, and the functions and applications of electronic scales have expanded to a wider range of fields. With China's accession to the WTO, the openness of the economic market has increased. A batch of internationally advanced weighing products and technologies, such as quantitative packaging scales, automatic weight inspection scales, label pricing scales, computer combination scales, pressure resistant measuring coal feeders, as well as production technologies for strain gauges, weighing sensors, and weighing displays, have entered China. This will have a positive and significant impact on the further popularization and improvement of electronic scales.