LM-3189 - Laser Dust Monitor

LM 3189 is the mostcost-effective dust monitor model, equipped with a semiconductor laser. It isexcellent for measuring at the medium to long distances( 3 - 10 m) and mediumhigh concetrations. ( > 25 mg/m3).

   The system setup:

  • The transmitter unit L 318
  • The receiver unit R 318
  • The monitor unit M 318
  • Purge air unit or the external instrument airsource
  • Optional data logging software available


  • Direct continous measurement of opacity oroptical density
  • Small, lightweight and easy installation
  • No moving parts and simple optics for long lifeoperation
  • Light source is a semiconductor laser
  • Adjustable alarm values and alarm relay
  • Linear voltage output 0 - 1 V and current output4 - 20mA
  • Digital LCD-display and analogue display forD-value
  • 4 operation ranges (0 - 0.03 D, 0 - 0.1 D, 0 -0.3 D, 0 - 1.0 D)
  • Low maintenace requirements and small physicalsize due to simple optics

   Advantages of asemiconductor laser:

  • A very compact and intense light beam, thediameter is only a few millimetres. This means that only small hole, about20mm, are needed in the stack simplifying the installation and requiring lesspurge air for the transmitter.
  • Good stability and long life. In contrast todesigns that use more traditional light bulbs, needing constant compensation,the laser source is relatively immune to the aging effect. The typical lifespan of a semiconductor laser is up to 10 years.
  • Due to the high intensity of the laser thedevice can easily penetrate also higher dust densities
  • Operation with known, clearly defined wavelengths. This makes the theoretical calculations and their results morepredictable as opposed to conventional sources that operate over a broad rangeof wave lengths and whose spectrum changes with age.

   Typical applications:

  • Continuous particle emission control inapplications, where the measuring path is max 40 meters
  • Max. dust content 2 g/m3
  • This model is most commonly used in power plantsburning oil, coal or bio-fuel, in cement plants or in steel or iron furnaces