1. Introduction

Using pipelines instead of open channels has many advantages. Pipelines prevent loss of water by evaporation and seepage. Operation and maintenance costs are reduced because less land is waterlogged, and the need for canal weed prevention and removal is eliminated. Land that would be occupied by canals and embankments is available for crop production or other uses. Buried pipelines, compared to open canals, are safer for animals and people. In general, pipelines have a higher initial cost, but as the value of water, land, and labor increases, the use of pipelines becomes more economically feasible. Thus, accurate flow measurement in pipelines becomes increasingly important.

Pipeline flow can be measured in many ways. Selection of a particular installation depends upon specific local situations. The accuracy of flow measurements in pressure conduits can be very high. However, measuring devices and techniques must be properly selected, installed, used, and maintained.