• According to the back-scatter principle
• Quick determination of the smoke spot number
• Can be calibrated to smoke spot number 0 - 3
• Automatic soiling correction, automatic zero and control point check.
• Typical applications: Smoke spot measurement for light oil fired combustion plants.

The D-R 300 meters works according to the stray light method, which makes them extraordinarily sensitive even to lowest particle concentrations.

Its emission optics shape the modulated light of a long service life-halogen lamp into a cone beam, which in the exhaust gas duct lightens the smoke particles. The receiving optics detect, within a defined measuring volume,the stray light reflected by the smoke particles and map same on the optical sensor. This sensor converts the straylight into an intensity-proportional signal current. The stray light’s intensity is proportional to the particle concentration within the measuring volume.

The secondary digital evaluation electronics compute the particle concentration from the stray light received and the emitted light’s intensity.

The value computed is then indicated in a 4-digit display as a digital value and simultaneously emitted as an analog current signal. The measured result can be calibrated and indicated in smoke spot numbers (soot) (D-R 300) or in mg/m 3 (D-R 300-40).

The meter’s optics and electronics section is gas and dust-tight on its chimney-adjacent side. The heated optical boundary areas are kept free from soiling through a separate purge air fan.

For the purpose of checking its orderly functioning, the meter performs a control cycle in periodical 4hour time lapses, whereby the zero point, the soiling of optical boundary areas as well as a reference value are measured and indicated automatically. If necessary, the subsequent measuring values are corrected. If the correction surpasses a certain value, the system will generate an error signal.

By TA Luft, light crude-fired plants of a capacity of between 5 and 25 MW are to be equipped with a measuring system, which shall continuously detect flue gas turbidity and with adequate certainty determine the smoke spot numbers (soot).

The DURAG D-R 300 / D-R 300-40 meters comply with these requirements. It is installed directly at the flue gas chimney and optically monitors flue gas turbidity on a continuous basis.

The measured values are registered on a recorder and limit value exceedings are reported without any delay. This permits taking the necessary measures within the regulation system of a furnace plant so as to safeguard realization of the limit values prescribed.

Registration Type tested to the guidelines of the Federal Ministry for Environ-ment, Nature Conservation and Reactor Safety on suitability testing of measuring equipment for continuous measuring of emissions.

D-R 300 Smoke Spot Number (Soot) Meter

Test report # 936 800002 of TÜV Rheinland, Cologne

Itemized in the list of suitable measuring instruments for continuous registration of emissions. GBMI # 37 of 1991.

D-R 300-40 Dust Concentration Meter

Test report # 936 801004, # 936/803011 and # 936/804020 of TÜV Rheinland, Cologne

Itemized in the list of suitable measuring instruments for con-tinuous registration of emissions. GBMI # 45 of 1992 and GMBI # 33 of 1995.