AFS 155 – Oil Thread Leak Tester

EN 1822-4, ISO 2463-4

The oil thread test mentioned in ISO 1822-4, appendix A is used for visual proof of the absence of leakage of HEPA filters. This simple quality test procedure may be an alternative to the scan method.
The oil thread test (DOP Test) is also applicable if the scan method is not fully applicable because of the filter design (e.g. V-shaped arrangements).
For scanning of HEPA and ULPA filters, Topas offers the Filter Scanning Test Rigs AFS 150 and AFS 152 – well proven and reliable solutions.


  • Cost-effective solution for leak testing of filters ranging up to group H (filter class H13 and H14)
  • Easy manual operation
  • Constant test conditions according to EN 1822%u20114 due to pre-adjustable test parameters
  • Effective testing of larger numbers with pre-adjusted test parameters
  • Flexible and easily configurable filter holder in case of different filter dimensions
  • Portable due to compact size