Balance flowmeter is a kind of differential pressure (DP) flow instrument. The working principle is the same as other differential pressure flowmeters. It is based on the principle of energy conversion in a sealed pipeline: The square root of the pressure is proportional to the flow and the difference in the pipeline in the case of an ideal fluid. The flow in the pipe can be calculated according to the equation by measuring the differential pressure value. The balanced flow sensor is a multi-holes throttle rectifier installed on the cross section of the pipe. The size and distribution of each hole are based on customized with special formulas and test data, called function holes. When the fluid passes through the hole in the shape of the disc, the fluid will be balanced and rectified, and the eddy current will be minimized to form an approximately ideal fluid. Through the pressure-receiving device, a stable differential pressure signal can be obtained, according to the law of mass conservation and energy in fluid mechanics. The law of conservation calculates the volumetric flow and mass flow of the fluid.