Acoem DSL-800 laser backscatter particulate monitor: The newest US EPA-complaint solution for measuring chimney stack emissions


As part of its commitment to continually evolve its offering for precision monitoring — especially in support of industries in regions working towards cleaner emissions standards —Acoem is proud to release its next generation laser backscatter particulate monitor, the DSL-800.


Monitoring solutions that have the power to affect positive environmental change

The DSL-800 is the result of several years of research and development by our specialist emissions team in the UK, supported by Acoem’s global expertise and 30 plus years’ experience in designing fit-for-purpose systems tailored for CMS applications around the world.

Verification testing was performed in the field at a third-party waste incineration plant where the instrument was mounted onto a four-metre-wide stack after an electrostatic precipitator. Over a period of eight months in 2021-2022, the data analysed from the extensive testing period confirmed that the DSL-800 laser backscatter particulate monitor is compliant with the requirements of the USEPA PS-11 (“Specifications and Test Procedures for Particulate Matter Continuous Emission Monitoring Systems at Stationary Sources”).

Precision emissions control at your fingertips

As an optical instrument, the DSL-800 has been designed to monitor the concentration of particulate matter passing through a duct, stack or flue of industrial combustion or air filtration processes, providing in situ measurement directly in exhaust gas flow.

It delivers accurate measurement readings, operating within a compliant performance range of 0-150mg/m3 when calibrated against standard reference measurements.

Intelligent unit with communication and outputs available directly from the head

The laser backscatter method comes with a number of significant benefits to users. First and foremost, being a single transceiver (TRX) head unit makes installation much easier, with only one head mounted on one side of the stack. The TRX head emits a beam of red laser light into the stack and automatically detects any light backscattered from suspended particles in real-time. The head’s configuration measures the light scatter from well into the stack, yet it remains insensitive to scatter from the far wall meaning that a light dump is not required.

No alignment is necessary, saving both time and effort, and distinctive plug and socket connection further simplifies installation with no cable glands. A smart analyser, it operates as a “stand-alone” instrument with all electrical connections (including outputs such as the alarm relays, 4-20 mA analogue outputs and ModBus) at the TRX head. The accessible latched head and lid design of the TRX makes cleaning and maintenance of optical surfaces easier too. The monitor is set up and controlled via Acoem’s supplied utility software, installed on a PC or laptop, and connected via the USB connector on the TRX.

On board temperature measurement provides stability over the operating temperature range and the monitor has the capability to perform automatic zero and span checking. Featuring rugged 316L stainless steel construction and an LED display to view measurements, operational status, alarms and maintenance requirements, the DSL-800 is the ideal instrument to ensure accurate management of:

  • process control
  • performance of your filtration system – alerting you to anomalies or requirements for maintenance
  • data that your process is operating within standards for regulatory compliance.

Available in three path length variants, the DSL-800 offers a tailored solution to suit the internal diameter of individual chimney stacks measuring from 0.5 metres to 4 metres.

The ideal instrument for systems integrators

For systems engineering firms and consultants who provide integrating monitoring solutions for various combustion-based industries – including power plants, distilleries, oil and gas, waste, smelting and cement manufacturing – the DSL-800 is an essential component to any holistic monitoring regime. As added value instrument it complements and works effectively with devices to measure flow, gases, humidity and temperature. All data can be fed back to a central computer for collation and reporting.

The optional DSCU operator interface for greater flexibility

A ground level operator interface and control unit – a DSCU – is also available. With the addition of a DSCU all power supply and output connections are made within the DSCU rather than the TRX. A wall mounted control unit, it consists of a numeric / directional keypad, a two-line LCD display and a terminal compartment, which allows full command and control of the instrument. The DSCU can be placed near the instrument or remotely, such as in a control room. With ground level access to alarm notifications, power and analogues outputs, the added advantage of a USB port allows you to connect up to eight monitors within a network using a single DSCU.

We are confident that the release of the new DSL-800 monitor gives combustion-based industries a greater choice when it comes to efficient, reliable and affordable emissions monitoring,” said Graham Jennings – Head of Sales & Marketing, CEMS.

“Being able to invest in a European designed and manufactured solution that is backed by decades of expertise and credibility in the environmental monitoring market makes complying with US EPA standards more easily achievable for a wider range of industries throughout the world,” he added.

For more information about the DSL-800 or other Acoem emission monitoring solutions, visit the DSL 800 product page or contact us.