TC Fluid Control Reed-chain Level Sensor

TC Fluid Control Reed-chain Level Sensor

The model FLR sensors with reed-chain technology are used for level measurement in liquid media. They work on the float principle with magnetic transmission.

The float's magnetic system in the guide tube actuates a resistance measuring chain that corresponds to a 3-wire potentiometer circuit. The measurement voltage generated by this is proportional to the fill level.

The measurement voltage is very finely-stepped due to the contact separation of the measuring chain and is thus virtually continuous. Resolutions between 5 and 18 mm are available depending on the requirements.



  • Process- and system-specific solutions possible
  • Operating limits:
    - Operating temperature: T = -80 ... +200 °C
    - Operating pressure: P = Vacuum to 80 bar
    - Limit density: ρ ≥ 400 kg/m3
  • Wide variety of different electrical connections, process connections and materials
  • Optionally with programmable and configurable headmounted transmitter for 4 ... 20 mA field signals, HART®, PROFIBUS® PA and FOUNDATION™ Fieldbus
  • Explosion-protected versions
  • Large scope of application due to the simple, proven functional principle
  • Process connection, guide tube and float from stainless steel 1.4571 or plastic
  • For harsh operating conditions, long service life
  • Continuous measurement of levels, independent of physical and chemical changes of the media such as: Foaming, conductivity, dielectric, pressure, vacuum, temperature, vapours, condensation, bubble formation, boiling effects, density change
  • Signal transmission over long distances
  • Simple installation and commissioning, onetime calibration only, no recalibration necessary
  • Level displayed proportional to volume or height
  • High repeatability
  • Interface measurement and overall level from ∆ density 50 kg/m³
  • Level sensors with reed-chain technology qualify as passive electrical equipment in accordance with DIN IEC 60079-11 and can be installed in “zone 1” hazardous areas without certification, so long as the equipment is operated in a certified intrinsically safe circuit with a minimum explosion protection of EEx ib.


  • Level measurement for almost all liquid media
  • Chemical, petrochemical, natural gas, offshore, shipbuilding, machine building, power generating equipment, power plants
  • Process water and drinking water treatment, food industry, pharmaceutical industry

Model Overview

Sensor modelDescription


Stainless steel                                                               Titanium

1.4571 1.4404  1.4435  1.4571  1.4571  1.4571  3.7035 (316Ti)  (316L)    (316L)   (316Ti)   (316Ti)  (316Ti)  (grade 2)

/ PP         / PA             / Ms







FLR-SReed-chain sensor, standard versionxxxxxxx   x
FLR-PReed-chain sensor, plastic version       xxx 
FLR-HReed-chain sensor, sterile version xx        


Sensor model


without Ex i


Ex d




Ex i + GL






Bureau Veritas


3-A      FM



Temperature range (process)
FLR-Sxxxxxxxxx -80 ... +200 °C
FLR-Px         -10 ... +100 °C
FLR-Hx       xx-20 ... +200 °C

Ex Approvals

Explosion        Ignition                   Model         Zone                  Approval number protection        protection type
ATEXEx iFLR-SZone 0/1/2KEMA 01 ATEX 1152 X II 1/2G Ex ia IIC T4 ... T6 - II 2 D T80 °C IP 6X
 Ex dFLR-SZone 1/2TÜV 13 ATEX 7399 X II 2G Ex d IIC T6 Gb / II 2 D Ex tb IIIC T80 °C Db
 Ex dFLR-SZone 1/2IECEx TUR 09.0002X -40 °C <= ta <= +55 °C Ex d IIC T6 Ex tD A21 IP 65 T80 °C
 Ex i + GLFLR-SZone 1/2KEMA 01 ATEX 1152 X II 1/2G Ex ia IIC T4 ... T6 - II 2 D T80 °C IP 6X + GL-14788-99 HH
 Ex i + DNVFLR-SZone 1/2KEMA 01 ATEX 1152 X II 1/2G Ex ia IIC T4 ... T6 - II 2 D T80 °C IP 6X + DNV-A-11452

Download Datasheet : TC Fluid Control Reed-chain Level Sensor

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