Changes in liquid densities can throw off readings. Plants commonly rely on differential pressure (DP) cells to measure level. Read this month's Plant InSites for advice on how to solve these level problems.
There's a myth in plants that HART offers little for Plant Control Systems and Enterprise Level Networks. But Ed Ladd from the HART Communication Foundation writes that by accessing the data in HART devices on a "full-time" routine basis increases performance, integrity, and reliability of plant control and enterprise level systems.
Author: Ed T. Ladd, Jr., HART Communication Foundation, Austin, Texas