Double pass dust monitor for monitoring dust emissions using ddp

The DSL-340 Dust Monitor is an optical instrument designed to measure the concentration of dust or particulate matter in exhaust gas passing through a duct, stack or flue.


Dynamic Detection Principle
Innovative Dynamic Detection Principle (DDP) measurement technique
Less susceptible to drift
Immune to gradual reductions in absolute intensity of the light signal so less susceptible to drift
Unit of measure
Measurement reading as mg/m³ (when calibrated against standard reference measurements)
Internal electronic calibration check capability
Rugged construction
Rugged 316 stainless steel construction
Interface options
Choice of interface options enabling easy integration
Free utility software
Free utility software for PC based set-up, control and data logging
Optional Operator Interface
Optional Operator Interface with different mounting configurations

See our technology in action.

Schedule a free demo to get a first-hand look at how our solutions support your business.


The DSL-340 uses the innovative Dynamic Detection Principle (DDP) which measures fluctuations in the intensity of a light beam, using a folded beam Transceiver/Reflector arrangement. Increased dust or particulate density in the stack causes the amplitude of these fluctuations to increase. When calibrated against standard reference measurements, the amplitude of this signal relates directly to the dust concentration in the stack and this can be presented as a reading in mg/m³.

Optional accessories

  • Operator interface (OI)
  • 90-260 Vac model available
  • Mounting flange installation kit
  • Laser alignment tool to assist with installation
  • Air purge blower kit (110 Vac / 230 Vac / 415 Vac)
  • Compressed air purge kit
  • Reference filters for routine calibration check of the instrument*


  • Significantly less susceptible to drift than standard opacity monitors
  • Better accuracy over shorter path lengths, i.e. smaller duct diameter
  • Simple to install, commission and operate with an excellent reliability record
  • Rugged design with no moving parts so low maintenance
  • Latched head and lid design to enable ease of access for installation and maintenance


Discover Acoem’s case studies

Why do you need DSL-340 ?

Ideal for monitoring dust levels in the exhaust gas of industrial combustion or air filtration processes.

Request pricing

Connect with Acoem

Contact us to learn more about our solutions, services, and training programs.

Would you like to…?