Durag D-R 820 Extractive Scattered Light Dust Monitor

The DURAG D-R 820 is an extractive dust monitor for wet sample gas to monitor low to medium dust concentrations.

Key Benefits

  • extractive measurement, continuous measurement, dilution of the sample
  • suitable for systems with variable gas speed
  • hyperkinetic sampling
  • allows calibration to measure the dust concentration in mg/m3
  • single sided mounting to the chimney
  • automatic zero and reference point check
  • automatic measurement and correction of contamination of optical surfaces
  • laser light source with long lifetime
  • easy installation, adjustment and maintenance without a PC
  • local control panel and LCD display.


Suitable for dust concentration measurement

  • at garbage, hazardous waste and sewage sludge incinerators
  • at power stations with gas, oil, coal or co-firing
  • at systems behind the flue gas scrubber
  • at systems behind de-sulfurization
  • at systems with low exhaust temperature and constant or occasional dew point.

Download Specifications


Stack, Process & CEMS


measurements scattered light value, allows calibration as dust concentration in mg/m3
sample gas air, flue gas, non flammable process gas
dust concentration**
(typical values at the site)
1 – 15 / 2 – 50 / 5 – 100 / 10 – 200 mg/m3
flow speed 1 – 35 m/s
duct diameter > 0,4 m
sample gas temperature -25 to 220°C
sample gas pressure -30 to +2 hPa, others on request
sample gas moisture > 100 % relative humidity, max. 30g/m3 H2O as aerosol
ambient temperature -20 to +50°C, others on request
conformity 2000/76/EG WID / 17. BImschV
2001/80/EG LCPD / 13. BImschV
Measuring principle extraction of sample gas, dilution and heating to vaporize H2O aerosols. Consequent measurement of light intensity being scattered in forward direction by dust particles
light source laser diode, red 650 nm
type in situ, mounted at stack, probe in contact with sample gas
system components D-R 820F P probe incl. extractive system
D-R 820F blower unit
D-R 820F SU Supply, control and display unit
measuring range can be parametrized
expanded uncertanty acc. to EN 14181 / EN ISO 14956 / EN 15267-3 better than 1,5 mg/m3 at particle size 1-2mü
output range scaling of scattered light values in mg/m3, assigned to analog output, range switching to 2nd range as option (ratio 1:3), display of measured values in mg/m3
process connection flange similar to DN80, PN6, pitch circle 150mm, tube ID = 100mm


power supply 200-264 VAC, 1.500 VA, 24 VDC, from D-R 820F SU,
others on request
protection IP 55
dimensions (h x w x d) 1.050 x 600 x 1.500 mm (1.000 mm immersion depth)
material housing: FRPl
probe: 1.4517, hastelloy 2.4610*
weight ca. 45 kg
output signal 4 – 20 mA / 500 Ohm
status output 4 x relay, max. load 35V 0,4A
status input 1 x dry contact, purge
power supply 230 / 400 V, 50Hz 3L, N, PE, 3 x 16A, 3.500 VA
supplies D-R 820F P and D-R 820F Blower, others on request
protection IP 55
dimensions (h x w x d) 400 x 600 (1.200***) x 410 mm
*** width if cabinet is open
material sheet steel, painted RAL 7035
weight ca. 20 kg
power supply 2 x 230/400 V 50 Hz, 3L, PE, from D-R 820F SU
others on request
protection IP 65
dimensions (h x w x d) 600 x 800 x 400 mm
weight ca. 40 kg
Bemerkung * variants
** the suitability of the D-R 820F for the listed ranges depends on the kind of dust and the size distribution
Subject to technical modifications!

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