The rotary blade level indicator IRP observes the filling level as a limit switch. It can be used as indicator for dusty and powdery, granulated and grainy bulk goods like dust, flour, grain, sand, plastic, etc. with a grain size up to 20 mm, bulk density up to 1 t/m3 and a height of product up to 5 meters. Higher densities and higher height of products to be consulted.

The rotating measuring blade, projecting into the silo or container, is driven by a gear motor. If the bulk material reaches the measuring blade, the rotation will be hindered, and it will be stopped. The return torque turns the pivoted motor from its end position and actuates the signal switch. A second switch turns off the motor off.

If the filling level of the bulk material sinks, the blade becomes freely again and a spring will turn the motor back into its original end position. Thereby, the motor will be turned on again and the signal switch will be switched back.

There are models that can be mounted horizontally or vertically into the silo.

The standard form is mounting the device with a flange, drilling holes on the silo to allow the mounting of the controller using screws, rods, fasteners, or nuts. If the flange was not requested, the thread is 1" 1/4 or 1" male, depending on the model, and can be fixed using 1 or 2 nuts or introducing it into a threaded socket with a maximum of 25 mm length. If it is larger, the bulk goods have the possibility to deposit in the thread socket. This could provoke that the device becomes useless.

Protection roof
The blade must not be hit by the filling stream. To avoid this, deflect the filling stream or install a deflection screen or a protection roof. It is also recommended to install a protection roof when the controllers are used as empty-indicator or medium-indicator in silos where vaults could be formed or where high loads above it could exist.


Approximate measures given in mm.

Technical data

NameRotary blade indicator
TypeIRP – ref: 2110-...
IRP Retén – ref: 2111-...
Measuring blade speed5 rpm
Switching voltageStandar 230 V AC (50 – 60 Hz)
(Under request 115 V AC, 48 V AC, 24 V AC, 24 V DC conversion of alternating current through a converter)
Power consumption3 VA on AC; 3 W on DC
Density of the product0,01 t/m3 – 1 t/m3
Maximum pressure-0,5 bar – +0,5 bar
(Under request up to +1 bar with sealing ring of Stainless Steel-PTFE-Viton)
Cable entry2 of M20x1.5
Max. voltage of contact250 V AC
Switching function1 NA + 1 NC
Capacitity of the contact2 A / 250 V AC (for resistive loads)
For inductive or capacitive loads reduce at 50%
Ambient temperature-20 °C – +60 °C
ProtectionIP65 according to DIN EN60529
Weight0,8 Kg depending on the model
Housing and capGlass reinforced ABS
Flange connectionAluminium or Stainless Steel
(under request)
Zincated Steel or Stainless Steel
Measuring bladeS.S. 1.4301, shaft 1.4305
(Under request special models of S.S. 1.4401 or Plastic)
Sealing ring
IRP-RStainless Steel-PTFE-Viton
Rod shaftStainless Steel
Protection tube shaftZincated Steel
(Under request Stainless Steel)

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