KEEPING A LEVEL HEAD.

Increasing costs of materials and storage combined with a growing awareness of hazards to personnel, plant and the environment caused by overspill and leakage are leading to a more widespread use of level monitoring techniques throughout industry. There are over 20 methods of level monitoring ranging from the simple float, dip stick and electrical conductivity systems through the capacitance technique, to the ultrasonics, microwave and radiometric systems. In the interest of reliability, sensors are moving away from mechanical and electromechanical equipment to solid state electronic instrumentation. The article reviews level measurement techniques.