Versatile double membrane level indicator. Is to be used to control the maximum or minimum level of bulk solids in silos or vessels where an additional protection of the membrane is required. Due to the double membrane, the device can still work unless the erosion or breaking of the exterior membrane.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
TypeCD-2M AT – ref: 2204-A
(Certified model MFD-NN)

CD-2M VITON AT – ref: 2204-A-703
(Certified model MFD-VN)
Certification B0 dustATEX II 3D Ex tc IIIB T80 °C Dc
Density of the product0,3 t/m3 – 2,5 t/m3
Ambient pressureAtmospherical
Maximum pressure+1 bar
Cable entryM20x1,5
Maximum voltage250 V AC
Contact function1 NO + 1 NC
Capacity of the contact15 A / 250 V AC (for resistive loads)
For inductive or capacitive loads reduce at 50%
Ambient temperature-20° C – +70° C
ProtectionIP65, according to DIN EN60529
Weight0,73 Kg
Sensitivity60 – 200 g adjustable
HousingGlass reinforced Polyester
Membranes2 membranes NBR
(Under request exterior membrane Viton)
CD2M extra diskPVC
Mounting ring and screwsZincated Steel
Cable glandPolyamide

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