Opacity monitors

Product types :

DSL - 220

Single pass opacity monitor for monitoring opacity and smoke emissions

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DSL-320

Double pass opacity monitor for monitoring opacity and smoke emissions

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DSL-460

Double pass opacity monitor for monitoring opacity and particle emissions

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Measuring the visible opacity of exhaust gases in ducts, stacks & flues

If an industrial smokestack releases excessive amounts of smoke, it indicates increased concentrations of dust and particulate, and poor combustion. Opacity monitoring is therefore an essential part of regulatory emissions compliance. Data captured by a continuous opacity monitor is critical to ensuring efficient and effective combustion and manufacturing practices.

How opacity monitors work

Acoem is a recognised specialist in the design and manufacture of high technology instrumentation for opacity monitoring. 

Our range of opacity monitors uses the light transmission technique to measure the visible opacity of exhaust gas in a duct, stack or flue. It features a high-intensity green light beam which is projected across the stack. Any dust, smoke or particulate present will attenuate the transmitted light and be measured based on the decrease in light intensity due to absorption and scattering. 

Opacity monitoring systems are insensitive to interference from other flue gas components since the beam spectrum is within the photopic region (400-700 nm) and most other flue gas constituents do not absorb in this spectral region.

 

 

Choose between single pass or double pass opacity monitoring equipment

Single pass continuous opacity monitors have a transmitter/receiver arrangement with the light beam emitted from the Transmitter passing across the stack to a Receiver. Double pass opacity monitors have a folded beam transceiver/reflector arrangement with the light beam emitted from the transceiver (TRX) passing across the duct to a reflector, which then returns the light to the transceiver.

Single pass opacity monitors are the simplest type of instrument and offer a very cost-effective solution to meet monitoring requirements. One advantage to single pass systems is that they are suitable for applications with long path lengths, for example large stack diameters. Acoem single pass opacity monitors can be used for path lengths of up to 20 metres.

Double pass systems are more suited to continuous emission monitoring as they have better sensitivity on smaller duct diameters. They are also simpler to install as electrical services are only required on one side of the stack. Double pass opacity monitors also allow for an in-situ zero and calibration facility.

Our continuous opacity monitoring equipment range

We offer three different continuous opacity monitors to suit various conditions and budgets:

  • Acoem DSL 320 — Double pass monitor that measures the visible opacity of exhaust gas passing through a duct, stack or flue from an industrial process or air filtration system
  • Acoem DSL 220 — Single pass monitor that measures the visible opacity of exhaust gas passing through a duct, stack or flue from an industrial process or air filtration system
  • Acoem DSL 460 — Double pass opacity monitor for measuring the visual opacity and/or concentration of dust and particulate emissions

 

See it in action

Learn more or schedule a demo.

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