Level measurement determines the height of a medium in silos, tanks or process vessels and converts it into an electrical output signal. The measured values are then transmitted to the process control system where they are used to monitor, control and automate industrial processes.

Various measurement technologies are available for level measurement. The most commonly used are radar level sensors, TDR sensors (guided wave radar), capacitive sensors and electromechanical plumb bob level systems. The most suitable measuring principle depends on factors such as the medium, process conditions, required measuring accuracy and the specific application.

Continuous level measurement is suitable for all applications where the current level of a medium must be monitored continuously. It is used for inventory monitoring, process control, dosing, consumption monitoring and the automatic filling and emptying of silos, tanks and process vessels. Continuous level sensors provide the level as a continuous measurement value, for example in millimetres, percentage or volume.

Level measurement can reliably monitor bulk solids, liquids and pasty media. Typical bulk solids include powders, granules, pellets, grain, sand, stone, cement and plastic pellets. Typical liquids include water, oils, chemicals and food products. Depending on the medium and process conditions, different measuring technologies such as radar, TDR, ultrasonic, capacitive sensors or electromechanical plumb bob systems are used.

Level measurement is used in almost every process industry. Typical industries include chemical, pharmaceutical, food and beverage, plastics, cement and building materials, power generation, water and wastewater, recycling, wood processing, mining, metal processing and animal feed production. It ensures the reliable monitoring and control of silos, tanks and process plants.

Depending on the measuring principle and sensor version, UWT continuous level sensors can operate at process temperatures ranging from −196 °C to +450 °C. Depending on the sensor, they are suitable for cryogenic liquefied gases, standard industrial processes and high-temperature applications.

Depending on the measuring principle and sensor version, UWT continuous level sensors can operate from vacuum up to process pressures of −1 to 400 bar. This makes them suitable for both vacuum applications and demanding high-pressure processes.

Point level detection monitors whether a predefined level has been reached or fallen below, for example for full, empty or overfill indication. Continuous level measurement, on the other hand, measures the entire level of a medium and provides a continuous measurement value from empty to full. The most suitable measuring technology depends on the application and the process requirements.

The selection of a level sensor depends on factors such as the medium (liquid or bulk solid), the measuring task (point level detection or continuous level measurement), temperature, pressure, vessel geometry, measuring range, material properties, dielectric constant (DK value), material build-up, dust generation, agitators and required certifications such as hygienic approvals, hazardous area approvals, SIL or WHG. Only the combination of these factors determines the optimum measuring technology.

Level measurements can be displayed directly on the sensor, on digital display units, touch panels or process control systems. Modern level monitoring solutions also enable remote monitoring via PCs, tablets or smartphones and support the networking of multiple locations. Standard communication interfaces allow integration into PLC, SCADA and ERP systems.