The document discusses selecting measurement and control devices for industrial processes. It covers several key considerations for proper selection including compliance with codes/regulations, process requirements, and engineering best practices. Some specific factors that must be considered are safety, performance, equipment location, power sources, and installation/maintenance. The document then provides an overview of level measurement techniques, categorizing them as measuring position/height, pressure, or weight. It describes some common level measurement methods like differential pressure and discusses important design considerations for each.