Electronic flow measurement as applied to the natural gas industry has advanced considerably over the last 30 years. Applications to address Upstream, Midstream and Downstream gas measurement technologies have become more complex. Over time it has become necessary to understand the fundaments that make up this ever changing environment. This paper will discuss the important fundamental parameters to consider when designing an Electronic Flow Measurement (EFM) system. Please be aware of the many variances to each specific design and understand this is only a fundamental paper to give new gas industry members a first look at the technologies that are required when considering an EFM design