By different working principle, flow meters are segmented into turbine, oval gear, rolling type. Turbine meters are suitable for light oil while oval gear for heavy one like engine oil. Both are with good accuracy and with electronic display. The rolling type, are divided into mechanical and electronic type, features in easy reading, as well as widespread application. All meters could be transfer fluids like diesel, gasoline, kerosene, or urea, and could be allocated with pumps or nozzles.
