RF Admittance Level Sensor: Overview and Measurement Principle

RF admittance is an advanced level control technology developed from traditional capacitive measurement. Compared with conventional capacitive methods, it provides higher reliability, better accuracy, stronger anti-fouling performance, and wider applicability. In essence, admittance is the reciprocal of impedance in electrical engineering, consisting of resistance, capacitance, and inductance. Since inductance is rarely significant in level applications, RF admittance can be understood as measuring admittance through high-frequency radio waves.

When in operation, the sensor probe, the vessel wall, and the medium together form an admittance value. As the liquid level changes, the admittance value also changes. The electronic unit then converts this change into a standard output signal, realizing precise level measurement. Soway’s RF Admittance Level Sensors, such as the SFC5 Series, leverage this technology to deliver accurate, reliable measurements even in challenging applications.

Difference from Conventional Capacitive Technology

RF admittance technology is developed on the basis of traditional capacitive methods but introduces key improvements in performance. The most important advancement is its ability to overcome the influence of conductive material buildup on probes. Traditional capacitive sensors are prone to false readings when buildup occurs, while RF admittance technology can simultaneously detect capacitance and resistance, effectively distinguishing between the true liquid level and interference from buildup layers.

As a result, Soway RF Admittance Level Sensors maintain accurate and stable level measurement even under severe fouling conditions, making them more reliable and versatile than conventional capacitive systems.