The PFG86 is a rotary paddle level switch designed to measure the levels of solid. It is constructed with a robust design perfect for dangerous operating conditions which has requirement for continuous rhythms. It is capable of detecting solid levels through controlling propeller’s rotation which is placed in the tank and drove by a synchronous motor. The propeller is capable of rotating when there is no material detected while when there is a material present the propeller rotates to switch working contact. Second contact shuts down the motor’s supply voltage. Falling of product level the propeller is released while the motor is powered ready for operation. This switch is calibration free, highly repeat able and low cost.