Scattered light dust measuring devices

Your Benefits

  • Reliable and proven dust measurement in wet gases
  • Economic operation due to very few consumable parts and very low installation effort
  • Very low maintenance since no moving parts come into contact with the aggressive gas
  • Very long service life due to intelligent design


The FWE200DH dust measuring device is designed to continuously measure dust concentrations in wet flue gas. The gas is extracted via a gas sampling probe and heated above the dew point. Droplets in the gas are vaporized, making it impossible for them to falsify the measurement results. The highly sensitive scattered light measurement principle enables accurate measurements even at low dust concentrations.

The FWE200DH meets the requirements of EN 14181 and EN 15267.

At a glance
  • For very low to medium dust concentrations
  • Gas sampling and return combined in one probe
  • Contamination check
  • Automatic monitoring of zero and reference point
  • Easy parameterization and convenient operation – optionally via supplemental remote unit
  • Integrated system diagnostics for early detection of maintenance requirements


Spare parts


Service & Support

Technical overview


Please note: The exact device specifications and performance data of the product may deviate from the information provided here, and depend on the application in which the product is being used and the relevant customer specifications.

  • FWE200DH measuring and control unit

    FWE200DH measuring and control unit

    Measured valuesScattered light intensity, dust concentration (after gravimetric comparison measurement)
    Performance-tested measurandsDust concentration
    Measurement principlesScattered light forward
    Spectral range
    640 nm ... 660 nm
    Laser, protection class 2, power < 1 mW
    Measuring ranges
    Dust concentration0 ... 5 mg/m³ / 0 ... 500 mg/m³
    Measuring ranges freely selectable
    Higher measuring ranges on request
    Certified measuring ranges
    Dust concentration0 ... 7.5 mg/m³ / 0 ... 10 mg/m³ / 0 ... 15 mg/m³ / 0 ... 50 mg/m³ / 0 ... 100 mg/m³ / 0 ... 500 mg/m³
    Response time (t90)
    0.1 s ... 600 s
    Freely adjustable
    ± 2 %
    Of measuring range full scale
    Process temperature
    PVDF gas removal probe≤ +120 °C
    Hastelloy gas removal probe≤ +220 °C
    Versions for higher temperatures on request
    Process pressure
    With SLV7 2BH1100 purge air unit–20 hPa ... 20 hPa
    Other pressure ranges on request
    Process gas velocity
    5 m/s ... 30 m/s
    Process gas humidity
    Max. 40 g/m³ liquid water without water vapour
    Ambient temperature
    –20 °C ... +50 °C
    Intake temperatures for purge air–20 °C ... +45 °C

    Approved for plants requiring approval

    2001/80/EC (13. BImSchV)

    2000/76/EC (17. BImSchV)

    27. BImSchV

    TA-Luft (Prevention of Air Pollution)

    EN 15267

    EN 14181

    U.S. EPA PS-11 compliant

    When options are used, agreement with local authorities may be required

    Electrical safetyCE
    Enclosure rating
    Measuring and control unitIP54
    Control unitIP65
    Analog outputs3 outputs:
    0/2/4 ... 20 mA, 750 Ω
    Electrically isolated
    Analog inputs6 inputs:
    0 ... 20 mA
    Not electrically isolated
    Digital outputs5 relay outputs (change-over contacts), potential-free:
    48 V, 1 A
    Digital inputs8 inputs
    Communication interface





    Type of fieldbus integrationTCP (via optional interface module, only one module possible per MCU)
    RTU RS-485 (via optional interface module, only one module possible per MCU)
    Via optional interface module (only one module possible per MCU)
    FunctionConnection to SOPAS ET software or OPC server
    Proprietary service interface
    LC display and status LEDs on control and remote unit
    InputFunctional keys
    OperationMenu-driven operation via control unit or software SOPAS ET
    Dimensions (W x H x D)
    FWE200DH measuring and control unit813 mm x 722 mm x 286 mm (for details see dimensional drawings)
    FWE200DH measuring and control unit65 kg
    Sampling probe≤ 15 kg
    Material in contact with mediaPVDF, Hastelloy
    Power supply
    Voltage115 V AC
    230 V AC
    Frequency50 Hz / 60 Hz
    Power consumptionFWE200DH measuring and control unit: 800 VA ... 1,700 VA
    Air heater: ≤ 1,000 VA
    Sample gas line, heated: ≤ 300 VA
    Test functions

    Automated self-test (zero point, contamination, drift)

    Contamination limit values: Warning at 30%; fault at 40%

    Manual linearity test with reference filter


    FWE200DH mounting rack

    Air backwash

    Water backwash

    Sample gas line, heated

    Air heater

  • SLV7-1 purge air unit, 2BH1100, 1-ph

    SLV7-1 purge air unit, 2BH1100, 1-ph

    Gas flow rate
    30 m³/h ... 40 m³/h
    Ambient temperature
    –20 °C ... +45 °C
    Intake temperatures for purge air
    Electrical safetyCE
    Enclosure rating
    Dimensions (W x H x D)
    550 mm x 550 mm x 257 mm (for details see dimensional drawings)
    16 kg
    Power supply
    Voltage115 V AC
    230 V AC
    Frequency50 Hz / 60 Hz
    Auxiliary gas connections
    Purge air40 mm
    Test functionsPressure switch (switching point –35 hPa)
    Integrated components2-step air filter, type Europiclon, dust capacity 200 g
All technical data can be found accompanying the individual product