The thermal gas mass flowmeter is designed based on the principle of thermal diffusion, and adopts the constant temperature difference method to directly measure the gas mass, eliminating the compensation of temperature and pressure. Therefore, it has the advantages of small size, high digitization, easy installation, accurate measurement and so on. The lower limit of the flowmeter is very low, and it is widely used in the measurement and measurement of conventional low pressure pure gas. Because most of the hot gas structures are plug-in designs, they are extremely popular in special-shaped pipes (such as smoke tubes and square pipes) in large factories.

The liquid turbine flowmeter is a kind of velocity flowmeter designed according to the torque balance principle. Widely used in petroleum, chemical industry, metallurgy, scientific research and other fields of measurement, control system. Liquid turbine flowmeters with sanitary fittings can be used in the pharmaceutical industry.