Sump and Sewer Level Monitoring Float Switch Transmitter

The perfect solution for monitoring levels in sumps, drains and sewers, in particular those where there is high humidity or high level inlets that create splashing that could impact on the suitability of BDT types of level sensors.

Utilising a industry standard NAMUR DIN 19234 interface the unit is fully compatible with high quality floats such the Pepperal+Fuchs LFT1 family.

The transmitter is available as standard to ATEX Category 3, Zone 2 and for operation on 434MHz and 869MHz WBFM in line with the essential requirements of the Radio Equipment Directive RED 2014/53/EU.

Operating at a transmit rate of once every 2.5 seconds, this sealed to life to beyond IP68 (fully encapsulated) the deign can achieve a battery life of over 10-years. Further with its transmit duty cycle of less than 0.4% the design is fully complaint with Article 3.2 of the RED and fits comfortably within ERC-Recommendation 70-03 for spectrum occupancy.

Utilising the RDNET™ ultra-lean radio protocol, the unit is fully compatible with the existing RDN1000™ booster, receivers, repeaters and Gateways and can be supplied to emulate the characteristics of the highly successful BDT or FDT sewer monitors.

The FST is idea substitute for BDTs in applications of high humidity, open rain or where and operational hysteresis is desirable required using a single device. The cable type is PVC as standard making the unit idea for Water and Wastewater applications.


Wireless Float Switch

The FST Transmitter Complete with LFL1 NAMUR Float Switch

Cable length is 5m as standard and can be suppled shorter if required.

The FST can be used in conjunction with the Sentinel or Gateways receivers and data can be ported via Data Concentrators over TETRA, LAN or even Satellite Networks.

General Specification:

  • Transmitter Head
    • Sealed to IP68 using Encapsulation
    • ATEX Category 3 Zone 2 design
    • Ingres Protection > IP68  – Fully encapsulated
    • Transmitter Body – Antistatic black ASA
    • Transmit Antenna 1/4 wave permanent fixed flexible rubber coated
    • Transmit LED – 5mm with protection bezel
    • Read and Transmit rate 2.5seconds nominal
    • Number of Addresses 32-bit (4-billion combinations)
    • Integrated Tamper and Fault Alarms
    • Rolling Key Security
    • RDNET™ protocol WBFM Variant
  • Battery Technology:
    • Dual C-cell Lithium
    • 3.6V nominal
    • ATEX to EN-60079-11
    • Mounting bracket:
    • Stainless Steel with standoff crank
    • 140mm W x 110mm H
    • Mounting Centre 125mm (4 7/8in) x 52mm (2in)
    • Weight < 1.2Kg including 5m of cable
  • Float Switch:
    • Manufacture: Pepperl+Fuchs
    • NAMUR  DIN 19234
    • Float operating temperature range -20C to + 50C
    • Cable length 0.5 to 5m (to order)
    • Float Diameter 8.6cm
    • Cable PVC
  • Radio Frequency Options:
    • 433.93MHz, 434MHz and 869.85MHz to ERC Recommendation 70-03
    • CE / RED  2014/53/EU Compliant
    • Transmit Duty < 0.4%

Ordering Part Numbers


where xxx = radio frequency 434.92 or 869.85MHz

n = cable length in m

-EX if ATEX required