Traditionally, the flow of natural gas has been measured by a combination of pressure transducers, smart transmitters, and flow computers. In the earliest types of natural gas flow measurement, transducers and transmitters were connected to flow computers to calculate natural gas flow rates. In terms of the real measurements, these transducers and transmitters served as the heart of flow computers. They still do in newer, smarter forms. The pressure transducer is basically a sensor that converts one form of energy, pressure or mechanical, to an electrical form of energy. These early transducers provided a low-level analog input, which limited the amount of information available to the flow computer or control system