ABSTRACT
Most of the tanks used in the process industry are equipped with level meters. However, in most level meter applications, it is not the 'level' that is wanted, instead the 'volume' of a stored product. The most commonly used principles of level detection are based on pressure measurement, float position or echo detection. Ultrasonic level meters are based on the time-of-flight principle. The meter will measure the time it takes for a sound pulse, generated inside the meter, to move from the meter to the surface below and back again. A radar level meter can use different measuring principles. A pressure sensor can easily measure a liquid level, but to do so it must be connected at the bottom of the tank. By replacing the resistance-measuring device with a capacitance-measuring device, also non-conductive liquids can be measured. In other aspects, these principles are very similar.
