When Bulk Needs Precision … Membrane Level Monitor

The Kobold NMF membrane level monitors are the best choice for cost-effective level monitoring of bulk goods in storage vessels. NMF indicates full and empty states, detecting the load demand for dusty, powdery, granular and grainy materials.

The housing, made of cast aluminium or glass-fibre reinforced plastic, carries the membrane retained by a screwed-on ring.  The weight of the bulk material presses against the membrane, which is pre-stressed with a spring, through to the support.  A plunger fixed to the membrane transfers the pressure directly to a micro-switch with changeover contact.  If the bulk material subsides, the membrane is relieved and the contact is switched back. Sensitivity can be spring-adjusted.  The monitor can thus be optimized for the specific type of fill, and the particular installation conditions.


  • Floating changeover contact with maximum 4 A at 250 VAC
  • Bulk materials from 0.3 up to 2.5 t/m³
  • Particle sizes up to 30 mm

Manifold applications

  • Mining and mineral processing
  • Feed and grain industries
  • Polymer production and processing

Application areas

Membrane level monitors allow economic level monitoring of bulk goods in storage vessels.
Used to indicate full and empty states and load demand for dusty, powdery, granulated and grainy bulk goods, the devices are also suitable for use with bulk materials (0.3 to 2.5 t/m3) and particle sizes up to 30 mm. They operate faultlessly provided the bulk goods flow easily at not too acute an angle. Only such materials exert sufficient operating pressure on the detector fitted in the wall of the silo.

NMF key features:
Pressure: overpressure MAX: 1 bar
Max temperature: 200°C
Density: up to 0.05 kg/dm3
Material: NBR, Nitrile, FPM stainless steel (membrane)
Easy to install, self-cleaning, suited for universal use, versatile service


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