D-R 320

The new generation scattered light dust monitor

The new scattered light dust monitor to detect lowest to medium dust concentrations in dry flue and process gas.

The D-R 320 is based on the back-scattered light principle. Thereby the light of a red laser diode illuminates the dust particles in the measuring volume of the flue gas duct. The light scattered backward by these particles is detected and evaluated.

A unique feature of the D-R 320 is the automatic background light compensation with means of a patented optical system with dual detector. This allows for an easy and quick Installation without any adjustment. A light trap is not required.


  • single sided installation on a standard flange
  • easy startup without adjustment
  • automatic background light compensation without light trap
  • automatic zero and reference point check
  • automatic contamination control and correction
  • integrated purge air regulation and purge air control
  • minimum maintenance
  • EN 15267 certified
  • digital interface according to VDI 4201-3


Continuous emission monitoring, e.g:

  • on incineration plants generally
  • on plants according to IED 2010/75/EU
  • on waste, hazardous waste and sewage sludge incineration plants
  • on cement manufacturing plants
  • on power plants with gas, oil, coal or co-firing
  • on plants for the incineration of biomass


Monitoring of:

  • ventilation units
  • filter units

Technical Data

Sample gas typeAir, flue gas, non flammable process gas
Sample gas temperature0…600 °C (+32…1112 °F)
Inner duct pressure-50...+50 hPa
Sample gas relative humidity0...95% RF, non-condensing
Stack/duct inner diameter>0,7 m (>2,3 ft)
Measuring principleBack scattering
IED 2010/75/EU
US EPA 40 CFR 60 PS11
CertificatesCE, QAL1 EN 14181 / EN 15267-1 / EN 15267-2 / EN 15267-3, MCERTS
Measuring locationIn situ, mounted at stack, device is not in contact with sample gas
Measuring sequenceContinuous
System componentsD-R 320 M measuring head, sender/receiver unit
D-TB 200 supply unit
D-ISC 100 universal operation unit (option)
Self-check, protective functionsAutomatic zero and reference point check
Automatic contamination correction
Integrated purge air monitoring
Integrated purge air regulation
Fully-integrated fail safe shutter for protection at purge air failure (option)
Physical measuring valueScattered light units, calibrated as dust concentration
Measuring range dust concentrationmin. 0 …5 mg/m³
max. 0 …200 mg/m³
Output range dust concentrationOutput range freely programmable. Any range within the measuring range can be assigned to the analogue output.
Certified measuring rangesDust concentration
0...7.5 mg/m³
Integration time1...180 s, programmable
Light source, spectral rangeLaser diode, red
Process connectionDN100 PN6 / ANSI 4“ 150lbs RF
Single-sided, on a standard flange in any orientation.
No adjustment at site required; no light trap required.
Digital interfacesRS 485 Modbus RTU, bi-directional communication, USB (Service)
Analog outputs1x 4-20mA, 400 Ohm, isolated, assignment parameterisable
Digital outputs2 x contact NC/NO, permissible load 60 VDC / 30 VAC / 0.5 A,
function can be assigned. Typically: maintenance, failure
Power supply24 VDC, 0,5 A
OperationD-ISC 100 universal operating unit (option),
Service software D‑ESI 100, incl. remote access via web interface (option), requires PC with Windows XP® or Windows 7® OS
Access via USB
Ambient temperature (operational)-40…+60 °C (-40…+140 °F)
IP protection class (IEC 60529)IP65
Dimensions (HxWxD)200 x 190 x 260 mm
200 x 190 x 410 mm (variants)
WeightDepending on version, approx. 15 kg
Material1.4571 / 316Ti, painted blue RAL 5017
Power supply90...264 VAC, 48...62 Hz
Air supply capacityIntegrated blower
IP protection class (IEC 60529)IP65
Dimensions (HxWxD)480 x 450 x 320 mm
Weight12 kg
MaterialStainless steel 1.4301
Electrical connections1x USB
1x DURAG device connector M23 (option)
Digital interfaces1x USB (service)
1x DURAG Modbus
1x Modbus RTU / RS-485 (optional extension module)
1x Profibus DP (optional DIN rail converter)
1x Modbus TCP (optional software module)
Analogue outputs1x 4...20 mA, 400 Ohm, isolated, assignment programmable
up to 17x with extension modules (option)
Analogue inputsNone (standard)
16x with extension modules (option) 0…20 mA, 50 Ohm, zero point programmable
Digital outputs3x relais output, contact NC/NO, permissible load 48 V, 0,5 A potential free, assignment programmable
up to 35x by extension modules (option)
Digital inputs1x digital input (standard), potencial free, assignment programmable
up to 33x by extension modules (option)
Power supply90...264 VAC, 48...62 Hz, 200 VA
Display, status LEDsGraphical LC display 120 x 92 mm,
5 LEDs for status display
Service software D‑ESI 100, including remote access via web-interface (option), requires PC with Windows XP® or Windows 7® OS
Remote access via USB / Modbus RTU (option) / Modbus TCP (option)
Ambient temperature (operational)-20 ... +50 °C (-4 ... 122 °F)
-40 ... +60 °C (-40 ... 140 °F) (option)
IP protection class (IEC 60529)IP65
Relative ambient humidity≤ 95% RF, non-condensing. Use weather protection hood for ≥ 95% RF
Altitude≤ 2000 m
EX zoneZone 2 (option)
Dimensions (hxwxd)220 x 335 x 145 mm
286 x 335 x 145 mm (incl. cable glands)
Weightapprox. 5 kg
MaterialStainless steel 1.4301, painted blue RAL 5017
  • The suitability of the D-R 320 for the listed ranges depends on the kind of dust, the size distribution and the duct diameter.
  • Subject to technical modifications.

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