Reinforced membrane level indicator to be used to control normally the medium or minimum level of bulk solids in silos or vessels. The models are certificated for use in potentially explosive Dust atmospheres hazardous areas.

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 have a regulation system by a spring that allows the adjusment 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.

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 given in mm.

Technical data

NameMembrane level indicator
TypeAD INOX AT ref: 2212-A-003
(Certified model MFB-EA)
CertificationB0 Dust: ATEX II 3D Ex tc IIIB T83° C Dc
Density of the product 0.3 t/m3 – 2.5 t/m33
Ambient pressureAtmospherical
Maximum pressure+ 0,5 bar
Cable entryM20x1.5
Maximum voltage250 V AC
Contact function1 NO + 1 NC
Capacity of the contact4 A / 250 V AC (for resistive loads)
For inductive or capacitive loads reduce at 50%
Product temperature -20º C – +200º C​
Ambient temperature -20º C – +70º C​
Weight1,85 Kg
Sensitivity 200 – 500 g adjustable
HousingAluminium, RAL 7001 coated
Membrane:Stainless Steel 1.4301
Mounting ring and screwsAluminium ring, RAL 7001 coated and screw Zincated Steel
Cable glandNiquel-plated Brass

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