Energy is divided into primary energy (coal, crude oil, coal bed gas, petroleum gas and natural gas), secondary energy (electricity, coke, artificial gas, refined oil, liquefied petroleum gas, steam) and energy-carrying working substances (compressed air, oxygen, nitrogen, hydrogen, water), etc.
Energy measurement is an important means to manage energy scientifically, save energy and reduce consumption, and improve economic efficiency. Flow meter is an important part of energy metering instrument. Water, artificial gas, natural gas, steam and oil, which are commonly used energy, use a huge number of flowmeters. They are indispensable tools for energy management and economic accounting.