rotary paddle level switch / bulk solids

They are used for the level control in containers holding
product in powder or granule form. In the standard version
the body is made of plastic material, in the ATEX version the
threaded mounting part is made of aluminium.
The functioning is based on the slow rotation of a syncronous
motor which turns the paddle which is placed in the
container.
In the absence of material the paddle turns, material coming
into contact with the paddle causes a breaking effect which
slows down the motor and in turn causes the unit to switch.
A second switch switches off the power off the motor.
The paddle starts to rotate again when the material in the
container falls freeing the paddle.