Palas - Fidas® 200 S 氣溶膠粒徑譜儀

The Fidas® 200 S has successfully passed suitability testing for continuous and simultaneous immission measurement of the PM10 and PM2.5 fractions in airborne particulate matter as per VDI 4202-1, VDI 4203-3, DIN EN 12341 (PM10), DIN EN 14907 (PM2.5) and has met the equivalency guidelines and received certification as per DIN EN 15267-1 and -2. The suitability testing results will be published in the German Federal Gazette and the certificates will be issued at in early 2014.

The Fidas® 200 S is currently the only optical immission system for online and simultaneous measurement of PM2.5 and PM10 on single particles (counting measurement method).

The Fidas® 200 S fine dust monitoring and immission measurement system enables the continuous and simultaneous measurement of PM1, PM2.5, PM4, PM10, TSP (PMtot), as well as particle number concentration and particle size. It is incorporated into an IP65 weather-proof housing. As a result, the Fidas® 200 S is able to be operated as a completely independent, stand-alone device for outdoor measurements, e.g. on the Zugspitze (Germany's highest mountain) or on the North Sea coast.

The Fidas® 200 S uses the recognized measurement technology of optical light scattering of single particles and is equipped with an LED light source with highly stable output and long lifetime. It is also equipped with a filter holder for the insertion of an absolute filter (47 or 50 mm in diameter). This enables a subsequent chemical analysis of the composition of the aerosol, for example, or an on-site gravimetric validation.

The Fidas® 200 S functions with a volume flow of 0.3 m3/h and is equipped with a Sigma-2 sampling head as per VDI 2119, which enables representative measurements even under strong wind conditions. The sampling system includes a drying system (intelligent aerosol drying system – IADS) that prevents measurement inaccuracies caused by condensation effects resulting from high humidity. In addition, a weather station provides reliable results for temperature, atmospheric pressure, and relative humidity.

Palas® offers remote maintenance and online data access for the Fidas® measurement systems at

Design and function

Figure 1 presents the design of the Fidas® 200 S fine dust measurement system. It comprises a Sigma-2 sampling head that enables representative measurements even under strong wind conditions and an intelligent aerosol drying system (IADS) that uses a drying unit that is dynamically controlled in relation to relative humidity and outside temperature in order to prevent measurement inaccuracies caused by condensation effects resulting from high humidity.

Figure 1: Design of the Fidas® 200 S fine dust measurement system

The actual aerosol sensor is an optical aerosol spectrometer that determines the particle size using Lorenz-Mie scattered light analysis of single particles. The single particles move through an optically differentiated measurement volume that is homogeneously illuminated with polychromatic light. Each particle generates a scattered light impulse that is detected at an angle of 85° to 95° degrees. The particle number is measured based on the number of scattered light impulses. The amplitude of the scattered light impulse is a measure of the particle size diameter.

The lower detection limit for immission measurement was able to be reduced to 180 nm through improved optics, higher light density using a new white LED as the light source, and improved signal analysis (logarithmic analog digital converter). This enables greatly improved detection, especially of smaller particles, which are mainly found at high concentrations near roadsides (see Figure 2).

Figure 2: Higher sensitivity with the Fidas® fine dust measurement system for the 0.18 – 18 μm particle size range

The better the classification accuracy and the resolution capacity, the more accurate the definition of the particle size distribution.

The new, digitized, electronic signal analysis system enables the rapid identification and correction of coincidence, as necessary. Multiple separation curves can be used simultaneously for the same size distribution, which enables the simultaneous output of PM10, PM2.5, PM1 (and others).

Figure 3: Comparison of the algorithms for conversion of the particle size distribution by PM values

In order to convert the measured values into a mass or mass fraction, the high-resolution particle size distribution in each value is multiplied by a correlation factor that reflects the different sources (e.g. combustion aerosols, tire wear, pollen) of the environmental aerosol (see Figure 3).

Figure 4: PM10 reference equivalence function of the Fidas® 200 S in comparison with a reference small-filter device during the course of suitability testing from the "Report concerning the suitability testing of the PM10 and PM2.5airborne particulate matter components on the FidasR 200 S immission measurement system manufactured by PALAS GmbH, TUV report no.: 936/21218896/A".

* Additional, non-certified measurement ranges, e.g. 0.4 – 40 μm and 2 – 100 μm, available upon request.


Particular Advantages

  • Certified in accordance with DIN EN 15267-1 and -2
  • Continuous and simultaneous real-time measurement of multiple PM values
  • Additional information on the basis of particle number concentration
  • High data availability (> 99% in TUV suitability test)
  • Adjustable time resolution starting at 1 minute
  • Light source: LED with high stability and long lifetime
  • Remote maintenance and data retrieval
  • Integrated data logger for data backup (even in the event of power failure)
  • Long service life
  • 2 pumps operating in parallel for additional reliability in terms of data availability
  • Little maintenance required, on-site size calibration possible
  • Intuitive, easy operation
  • Reliable functioning
  • No radioactive material
  • No consumables
  • Reduces your operating expenses!