Buyers Guide Directory

Level measurement is integral to process control in many industries. Level instruments, be it level indicators, level controllers or overfill prevention systems, are suited for applications in a wide variety of industries such as cement, food processing, packaging, factory automation, bottling, thermal power, chemical processing, pulp and paper, water and wastewater, textiles, metals processing and finishing and industrial process control. The water industry makes particular demands of level measurement. The widespread use of level control varies from sewage and effluent discharge, to reservoir level measurement and water treatment plant control and automation. Conductivity level switches, also known as the water level sensors, are used for water and liquid level measurement and works on the conductivity based level measurement principle. It works to maintain a constant water level avoiding material wastage in your process plant. Common applications include switching pumps on and off to avoid overflow, dry running and indicating water level in an empty tank to avoid wear and tear and production stoppage. Level measurement sensors fall into two main types. Point level measurement sensors are used to mark a single discrete liquid height–a preset level condition. Generally, this type of sensor functions as a high alarm, signaling an overfill condition, or as a marker for a low alarm condition. Continuous level sensors are more sophisticated and can provide level monitoring of an entire system. They measure fluid level within a range, rather than at a one point, producing an analog output that directly correlates to the level in the vessel. To create a level management system, the output signal is linked to a process control loop and to a visual indicator. Within these categories there are many variations and customers need to consider if they are measuring a liquid or solid, what are the application's temperature and pressure ranges are, what level measurement range is needed and whether analog, relay or digital display output is required. For example dipsticks for manual level measurement, primarily in cylindrical underground tanks, are especially suitable for fuel and diesel oil, whereas digital tank contents indicators are specially suitable for continuous level measurement in rainwater tanks and cisterns. The product portfolio for continuous level measurement covers both non-contact ultrasonic sensors (incorporate an analog signal processor, a microprocessor, binary coded decimal (BCD) range switches, and an output driver circuit) and contact ultrasonic sensors (consisting of a field-mounted sensor and integral solid state amplifier, contact ultrasonic sensors have no moving parts and require no calibrationand. Radar, ultrasonic and gravimetric technologies are available for the non-contacting applications. Capacitance, guided wave radar and hydrostatic technologies are available for the contacting applications. Point level measurement includes ultrasonic, rotating and vibrating level switches suitable from bulk solids to liquids.