Durag D-R 290 Optical opacity-dust monitor

The DURAG D-R 290 has been used successfully for more than 15 years in various applications as reliable and low maintenance opacity / dust monitor. Now in its 2nd generation, the D-R 290 is a certified optical transmission monitor to measure the opacity or dust concentration of flue gases with medium to high dust concentrations.

The D-R 290 uses the double-pass method according to the auto-collimation principle. The light beam traverses the measuring path twice. The attenuation of the light beam by the dust content in the measuring section is measured and evaluated.

Key Benefits

  • Continuous and contact-less measurement
  • Automatic zero and span check
  • Automatic measurement and correction of contamination of optical surfaces
  • Extremely powerful and stable super-wide band diode (SWBD) light source
  • Extremely low-maintenance
  • Fail-safe shutters with purge air monitoring as option
  • Certified according to EN 15267-3
  • Compliant with US EPA 40 CFR 60 PS1 and ASTM 6216

Advantages of the new generation

  • Digital Modbus interface according to VDI 4201-3
  • Convenient operation with remote access option
  • All settings can be changed without opening the device
  • Compatible with universal display and control unit D-ISC 100


Suitable for dust concentration measurement

  • on incineration plants
  • on power plants
  • on cement plants
  • in the metal industry
  • on plants according to IED 2010/75/EC
  • on converter plants and asphalt mixing plants
  • on plants for the incineration of biomass

Suitable for measuring the opacity of flue gas

  • on plants in accordance with U.S. EPA 40 CFR 60 PS1, special MCOC required
  • on cruise and container ships.

Suitable for measurement of dust load in warehouses


Download Specifications


Stack, Process & CEMS


Sample gas type Air, flue gas, non flammable process gas
Sample gas temperature Above dew point up to 250 °C (482 °F) standard,
optional up to 1000 °C (1832 °F)
Inner duct pressure -50…+20 hPa (optional higher)
Sample gas relative humidity 0…95% RF, non-condensing
Stack/duct inne diameter 1…18 m (3.3…59.1 ft)
Measuring principle Measuring the optical transmission of visible light which passed a measuring path twice.
Conformities IED 2010/75/EU
EN 13284-2, EN 14181
EN 15267-3
40 CFR 60 US EPA PS1
40 CFR 60 US EPA PS11
Certificates CE, COC QAL1 DIN EN 14181 / DIN EN ISO 14956 / EN 15267-3, MCERTS, Pattern Approval GOST R, Pattern Approval certificate Rep.of Belarus, Pattern Approval Certificate PRC, MCOC 40CFR 60 EPA PS1
Measuring location In-situ, non-contact
Self-check, protective functions Automatic zero- and span check
Automatic soiling correction
LED light source: no readjustment needed
Automatic fail safe shutter in case of purge air failure (option)
System components D-R 290 M xx2 measuring head
D-R 290 R xx2 reflector
D-ISC 100 Universal operating and display unit
D-BL purge air unit
D-R 290 E mounting flange with tube
D-SK fail safe shutter (option)


D-R 290 M 2nd-gen MEASURING HEAD
Physical measuring value Optical density/ extinction, opacity
Derived measuring values Transmission, opacity (SP), extinction, dust concentration in mg/m3, mg/Nm3 (after gravimetric calibration)
Measuring range opacity 0…20% … 0…100%
Output range opacity Freely programmable
Measuring range extinction 0…0.1 … 0…2.0
Output range extinction Freely programmable within the measuring range
Measuring range dust concentration 0…10000 mg/m3 (depending on calibration)
Output range dust concentration Freely programmable within the measuring range
Lowest detection limit 0.75% for measuring range 0…0.1 extinction
Combined standard uncertainty acc. to QAL1, DIN EN 14181 1.8%, related to the certified measuring end value 15mg/m3
Light source, spectral range 450…680 nm, SWBD LED white
Process connection Connection flange, bolt circle 100 mm, tube ID = 59 / 83 / 105 mm
Digital interfaces RS 485 Modbus RTU, bi-directional communication
Mini-USB (service)
Analog outputs 1x 4-20 mA, 400 Ohm, potential free, assignment programmable
Digital outputs 2x contact NC/NO, max. load 60 VDC /
30 VAC / 0.5 A
assignment programmable, typically: maintenance, failure
Power supply 24 VDC, 0.5 A
Ambient temperature (operational) -40…+60 °C (-40…140 °F)
IP protection class (IEC 60529) IP65
EX zone Option: Ex II 3G Ex pz II T4, Ex II 2G Ex px II T4
Dimensions (hxwxd) 370 x 190 x 400 mm
Weight 10 kg
Material Aluminium, painted blue RAL 5017
D-R 290 M 2nd-gen REFLECTOR
Process connection Connection flange, bolt circle 100 mm, tube ID = 59 / 83 / 105 mm
Ambient temperature (operational) -40…+60 °C (-40…140 °F)
IP protection class (IEC 60529) IP65
Dimensions (HxWxD) 370 x 190 x 270 mm
Weight 7 kg
Material Aluminum, painted blue RAL 5017

Request information or pricing

If you need a quote, specifications or technical info, or anything else – please submit the form below and one of our team of experts will happily get back to you within 24 business hours. 

  • This field is for validation purposes and should be left unchanged.

Related Products

.woocommerce .woocommerce-tabs h2 { display: none; }