RF-Capacitance Level Switch is the Capacitance level detector which is sometimes called an admittance level sensor. These sensors make use of a radio frequency balanced impedance bridge circuit to find out whether the probe is in touch with the process material whose level is going to be detected. The RF-Capacitance level switch is appropriate for application in liquid and solid mediums. The design and sensing electric unit makes it suitable for sticky media, large hoppers, and storage bins. The switch is easily thread mounted on the tank and is highly reliable in operation. The RF-Capacitance level switch consists of a guard section, upper solution, main probe, and grounding. It consists of a conductive obe which serves as one of the capacitor plates, and the vessel wall ich forms the other plate of the capacitor since it is also prepared for a conductive material. The isolation between these two plates of capacitors is provided via an insulating process material having a low dielectric constant. Now, for measurement purpose, an RF signal is applied between the two capacitor plates which cause a little flow of current from the conductive probe to the vessel wall via process material. The probe works as an antenna to sense the frequency. "When the level in the tank drops and the probe is exposed to the even less conductive vapors, the dielectric constant drops. This causes a drop in the capacitance reading and a minute drop in current flow. This change is detected by the level switch's internal circuitry and translated into a change in the relay state of the level switch"

• Suitable for sticky application solids powder