Control of solids

Membrane level indicators


Intended use:

Versatile membrane level indicator. Is to be used to control the maximum or minimum level of bulk solids in silos or vessels.

These controllers consist of a switch actuated by a membrane and it is recommended for dusty and powdery, granulated and grainy bulk goods like dust, flour, grain, sand, plastic, etc. with an easy flow and a bulk density from 0.3 to 2.5 t/m3.


The membrane must to be exposed to the material.

The movement of the switch is the result of the pressure exerted by the incoming bulk material against the membrane which forces the membrane to move backwards, reversing the position of the switch and the signal is used for example to control the transport system in the silo.

The models “A-100”, “AD”, “SR” y “CD2M” and the models with S.S. membrane have a regulation system by a spring that allows the adjustment of the sensitivity. Tightening the regulation nut to reduce the sensitivity and increase the strain of the material to activate the microswitch. Clockwise insensitive.

The models are adjusted at their maximum sensitivity. It is necessary to ensure the proper pressure to the membrane that returns the membrane when there is no product covering it.

Mechanical connection:

Drill holes in the silo or vessel and mount the indicator using screws, rods, fasteners or nuts M6 making sure of the easy flow of the material and ensure that the product leaves the membrane without product on it.


Approximate measures are given in mm.




Technical data:

Name Membrane level indicator  
Type CD ref: 2201...
Density of the product 0.3 t/m3 ... 2.5 t/m3  
Ambient pressure Atmospherical  
Maximum pressure +0.5 bar  
Cable entry M20x1.5  
Maximum voltage 250 V AC  
Contact function 1 NO + 1 NC  
Capacity of the contact 10 A / 250 V AC
(for resistive loads)
For inductive or capacitive loads reduce at 50%
Ambient temperature:    
CD standard -20 ºC ... +60 ºC  
CD with Aluminium housing -25 ºC ... +80 ºC  
Protection: IP53 / IP40 depending on the position of the cable gland  
CD standard 0.48 kg  
CD with Aluminium housing 0.95 kg  
Sensitivity 60 ... 1000 g adjustable
(Depending of the model. Consult your application to our Technical Department)
Housing Glass reinforced Polyester
(Under request Aluminium)
Membrane NBR
Under request Stainless Steel 1.4301
Mounting ring and screws Zincated Steel
(Under request Stainless Steel 1.4301)