i3 TrackPor Gold-coated Polycarbonate membrane

Gold-coated track-etched polycarbonate membranes are especially suitable for particle analytic procedures. These include the testing of indoor and outdoor air to measure levels of inorganic fibres such as asbestos in accordance with VDI guidelines 3492 and 3861 (VDI = Association of German Engineers) and with ISO 14966. BIA 7487 (BIA = German workplace accident insurance institution) also notes that levels of dusts and powders can easily be measured using track-etched filters. i3 TrackPor membranes are used for asbestos analysis of plaster, fillers and paints on house interiors and exteriors in accordance with VDI 3866 and 3877.

Because of the very even surface and the tunnel-shaped pores of i3 TrackPor membranes, particles remain on the smooth surface and can thus be examined microscopically. The membranes are coated with gold on both sides and correspond to current VDI standards. The gold layer on the top (shiny side) is about 40 nm thick while the gold layer on the matt side is about 20 nm thick and serves to stabilise the filter during the measurement process. The gold layer protects the polycarbonate filter during scanning electron microscopy, increasing the contrast and providing optimal conductivity.

i3 TrackPor track-etched membranes are also used in i3 TrackPor M, a single-use monitoring solution for asbestos analysis that is ready to use. As stipulated by VDI guideline 3492 the monitoring equipment is connected to a sampling device. The air is sucked through it for a few hours so that the particles settle on the gold-coated membrane. After the measurement has been carried out the gold membrane is removed in the laboratory and the dust present on it is burnt. Using scanning electron microscopy (SEM) the asbestos fibres are counted and the fibre types found are then identified and classified using energy-dispersive x-ray (EDX) analysis.

i3 TrackPor membranes are available in different diameters and pore sizes. The application areas include: 

  • particle analysis using SEM and EDX
  • counting nanoparticles
  • testing for technical cleanness
  • identification of fibre-shaped particles such as asbestos:
    • VDI guideline 3492 - in indoor air
    • VDI guideline 3877 - on surfaces
    • VDI guideline 3866 - in technical products
    • VDI guideline 3861 - in flowing pure gas
    • BIA process 7487 - asbestos in powder and dust
    • ISO 14966 - fibres in ambient air




Product information i3 TrackPor

Standard pore sizes

  • 0.2 µm
  • 0.4 µm
  • 0.8 µm

Standard diameters

  • 13 mm
  • 25 mm
  • 37 mm
  • 45 mm

Packaging units on request.

Individual pore sizes and diameters on request


Pore size

0.2 µm

0.4 µm

0.8 µm





Gold coating top/down

40/20 nm

40/20 nm

40/20 nm

Pore density

340 x 106/cm2

100 x 106/cm2

46 x 106/cm2


13 / 25 / 37 / 45 mm

13 / 25 / 37 / 45 mm

13 / 25 / 37 / 45 mm