ABSTRACT
The variety of choices facing an engineer confronted with a flow measurement application is vast. In nearly every case each category further subdivides into several distinctly different variants. For example, the positive displacement principle types include rotary piston, oval gear, sliding vane, and reciprocating piston. Comparison tables on some of the key parameters, such as accuracy, flow range, and operating temperature, are also provided. It is hoped that this information, together with the basic selection philosophy outlined, will assist in finding a way through the maze of meter types and in selecting suitable meters for specific applications. Differential pressure meters have the advantage that they are the most familiar of any meter type. They are suitable for gas and liquid, viscous and corrosive fluids. The yearly energy cost of operating differential-pressure-type flowmeters can in some cases exceed the purchase price of the meter.
