The rotary vane blade is connected to the clutch by the drive shaft. When the material is not in contact with the material, the motor maintains normal operation, and when the blade contacts the material, the resistance motor stops rotating. The detecting device outputs a contact while cutting off the power supply to stop the rotation. When the material drops, the blade resistance disappears, and the detecting device can be adjusted by the torque. Jointless steel pipe with hot-rolled, hot-rolled-cold drawn or otherwise produced pipe wall.

The rotary level switch is used as a level switch for solid material detection. The working principle is that the blade is connected to the clutch through the transmission shaft and uses a micro motor as a driving device to continuously rotate the blade. When the blade contacts the material, The resistance generated between the blade and the material overcomes the tension of the sensitivity adjusting tension spring to open the tension spring. At this time, the motor stops rotating, and the detecting device outputs a switching amount; when the material falls below the blade, the resistance generated between the blade and the material disappears. The sensitivity adjustment spring is reset to the original state, and the motor drives the blade to continue to operate normally again.