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Group short and long process aperture

D-R 320
Dust monitor

For continuous, contactless measurement of low to medium dust concentrations in dry flue and process gases. Also suitable for corrosive gases and potentially explosive atmospheres.


Functionality: Backward scattering

  • Continuous dust measurement
  • Smallest certified measuring range 0 … 7.5 mg/m3
  • Single-sided installation without optical alignment
  • Automatic control functions
  • Continuous, integrated purge air monitoring and control
  • Maintenance and linearity check without disassembly
  • Contactless measurement
  • Suitable for official emission monitoring
  • Reliable measurement of small dust concentrations
  • Space-saving and easy installation
  • Long life time and high availability under extreme plant conditions
  • Low maintenance
  • Emission measurement of dry flue gases at the stack
  • Temperatures up to 600 °C
  • Corrosive flue gases, plants with complex gas matrix
  • Measurement of dry process gases with small concentrations
  • Technical data
  • Explosion protection
  • System components
Measuring principleBackward scattering, single-sided installation, contactless and in-situ measurement
Measuring variableStray light units, calibratable as dust concentration in mg/m³
Measuring rangeMin. 0 … 5 mg/m³Max. 0 … 200 mg/m³
Certified measuring range0 … 7.5 mg/m³
Ambient conditionsInstallation location: Indoor or outdoor installation**Temperature: -40 … +60 °C-30 … +60 °C (ATEX)-20 … +60 °C (IECEx)
Operating conditions in ductTemperature: Max. 600 °CRelative humidity: 0 … 95%, non-condensingRelative pressure: -50 … +50 hPa -50 … 0 hPa (ATEX/IECEx)
Duct dimensionsMin. inner diameter: 0.7 mMax. wall thickness: 0.56 m
Interface*Analogue output: 1x 4 … 20 mA, max. 400 Ohm, potential-free (various parameters adjustable)Digital output: 2x NC/NO, max. 60 VDC, 30 VAC), 0.5 A (various parameters adjustable)RS 485 Modbus RTU, USBStatus display: LED
Operation and displaySoftware D-ESI 100*** orOperating unit D-ISC 100
Control functionsAutomatic zero point and reference point measurement, automatic contamination measurement and compensation, integrated purge air monitoring and control
Protective functionsIntegrated fail-safe shutter (optional)
Light sourceLaser, class II, < 1 mW at 650 nm

* Additional interfaces with D-ISC 100 operating unit

** Weather protection cover required for outdoor installation

*** Enables remote access via web interface, PC with Windows operating system required

ATEXII 2G Ex px op is IIC T4 GbII 3G Ex pz op is IIC T4 GcII 3D Ex pD III T70 °C Dc
IECExEx pzc IIC T4 Gc
Dust monitor D-R 320
Software D-ESI*
Terminal Box with purge air unit D-TB 200 or
Terminal Box without purge air unit D-TB 100** or
Operating and purge air unit D-ISC 100 P

* Enables remote access via web interface, PC with Windows operating system required

** External purge air supply required

  • Patented design, without alignment of optical components after installation
  • Mandatory
  • Recommended
D-TB x00
D‐ESI 100
D-ISC 100 xx2