D-R 320

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 without optical alignment
  • 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
  • QAL1 certified according to EN 15267-3
  • Compliant with US EPA 40 CFR 60 PS11
  • Lowest certification range 0...7.5 mg/m3


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
  • 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.


Universal display and operating units

The universal operating unit  Opens internal link in new windowD-ISC 100 allows the connection of several DURAG devices. It allows parameterisation and maintenance of all connected devices via integrated keypad or a connected PC and also supports remote access via intranet or internet connection.


Our  Opens internal link in new windowD-ESI Service and Parameterisation Software  assists you to manage all your DURAG sensors connected in one network system via a uniform graphical Interface.


Please contact your sales representitive for more Information.

Supply unit

  • Opens internal link in new window D-TB x00 in various versions
  • for voltage supply of one DURAG sensor
  • different housings available
  • version with integrated purge air blower available

Please contact your sales representitive for more information.

Purge air blower

  • D-BL xx in various versions
  • for supplying the measuring head with purge air
  • weather protection cover available as an option

Please contact your sales representitive for more information.

We offer various accessories such as weather protection covers for your sensor, reference filter sets, mounting flanges and so on to fit your application and to have all components from one source.

Please contact your sales representative for further information.

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