After years of research, in 1977, the American company MICRO-MOTION launched the U-tube mass flowmeter for the first time. This type of mass flowmeter showed its strong vitality as soon as it hit the market. Its advantages include the ability to directly obtain a mass flow signal, which is not affected by the physical parameters of the medium. The accuracy is ±0.4% of the measurement value, and some can reach 0.2%. It can measure a wide variety of gases, liquids, and slurries, especially suitable for measuring trading media such as liquefied petroleum gas and liquefied natural gas based on quality, making up for the shortcomings of electromagnetic flowmeters; because it is not affected by the velocity distribution on the upstream side, direct pipe sections are not required before and after the mass flowmeter. The disadvantages include that the processing accuracy of the mass flowmeter is relatively high, usually with a very heavy base, thus making it expensive; due to being prone to reduced precision from external vibration, attention should be paid to the selection of its installation location and method. Major domestic manufacturers include Shanghai Guanghua, Aermet, Chongqing Naide, etc.