VEGA South Africa’s 6 000 m2 head office and warehouse in Lanseria is equipped with a water storage solution, comprising two 10 000-litre JoJo Tanks as a backup system during water shortages. The VEGAPULS 31 radar level sensor and VEGA MET series level controller is used to manage them.
“The water tanks act as a municipal water back up system in times of water outages. Water from these tanks is used to cater for essentials like the flushing of toilets, cooking of staff meals in the kitchen and cleaning of offices,” explains Miguel Petersen, marketing manager, VEGA South Africa. The VEGAPULS 31 radar sensor is responsible for gauging the water level within the tanks, while the VEGA MET controller interprets these measurements from the sensor. It then uses this data to regulate the pump’s operation, primarily based on the tank levels. In this setup, the first tank is directly connected to the primary water supply line, receiving water from the municipality. It acts as a reservoir and is linked to the second tank. When the water level in the second tank drops to a certain point, indicating a low level, the pump is activated to transfer water from the first tank into the second tank. Once the tanks are full, the controller will stop the pump. This ensures a consistent water supply within the system without overspilling. 
“A particular advantage of the VEGAPULS 31 radar sensor for this application is that the sensor can measure levels in the plastic tanks from the outside through the tank wall. Another plus is that it can be calibrated remotely, which is necessary due to the height of the tanks,” adds Petersen.
The VEGAPULS radar sensor range is compact, and specifically designed for the water and wastewater industry. Certain sensors within the range have an IP68K rating and can be fully submersible in liquid. Ultrasonic versus radar technology The VEGAPULS sensor range uses radar technology instead of ultrasonic. Compared to ultrasonic measuring instruments, radar sensors measure unaffected by temperature fluctuations, vacuum or high pressures and are insensitive to contamination. The 80 GHz radar sensors also have good signal focusing. This makes it easier to separate measurement and interference signals – the measurement is much easier and more accurate. “Today, radar sensors can be found in all areas of everyday life, from simple motion detectors for door openers to complex distance sensors in vehicles. However, the requirements for industrial level measurement differ considerably. The radar microchip newly developed by VEGA has been specially optimised for the requirements of level measurement. Thanks to its small design, very compact sensors are now possible These are significantly less expensive and can replace the previous ultrasonic sensors in almost all applications,” adds Petersen.
