FEATURES
• Innovative Dynamic Detection Principle (DDP) measurement technique
• Immune to gradual reductions in absolute intensity of the light signal so
less susceptible to drift
• Measurement reading as mg/m3 (when calibrated against standard reference measurements)
• Internal electronic calibration check capability
• Rugged 316 stainless steel construction
• Choice of interface options enabling easy integration
• Free utility software for PC based set-up, control and data logging
• Optional Operator Interface with different mounting configurations
BENEFITS
• 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
THE TECHNOLOGY
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. 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.
APPLICATIONS
• Cement works
• Steel plants
• Air filtration processes such as electrostatic precipitators
• Other industrial applications with larger particle size and relatively high dust loading

TECHNICAL SPECIFICATION
Parameter Comment
Measuring Principle Dynamic Detection Principle, DDP (Scintillation)
Operating Wavelength 510 – 540 nm (green LED)
Measurement Reading Concentration (mg/m3)
Measuring Range 0 – 1000 mg/m3 (user configurable)
Path Length (duct diameter) 0.5 – 10 m (flange-to-flange separation)
Accuracy + / - 2 %
Flue gas flow rate ≥ 1.0 m/s
Resolution 0.1 mg/m3 (display resolution)
Damping 1 – 60 s (user selectable)
Drift with Temperature < +/- 0.5 %
POWER & AIR REQUIREMENTS
Voltage +24 Vdc (optional 90-260 Vac PSU available)
Nominal Current Consumption 400 mA
Power Up Current Consumption 400 mA
Purge Air Supply Volume 50 – 200 L/min (to each air purge body)
Purge Air Quality Suitably filtered, oil free and dry
INTERFACE OPTIONS
Serial Comms ModBus RTU via RS485
Internal USB (OI)
External USB (TRX)
Analogue Outputs 4.0 – 20 mA (isolated and scalable)
Relay Contacts 3 A @ 30 Vdc (signal level and service alarms)
PHYSICAL
Ambient Operating Temperature -20 – +55 °C (air temperature around the equipment)
Exhaust Gas Temperature Up to +600 °C (heat insulating gaskets included)
Ambient Operating Humidity 0 – 100 %
Ingress Protection IP65 for external use
Materials 316 Stainless Steel (powder coated)
Dimensions 153 x 120 x 122 mm (measuring head)
Weight 2.5 kg per head