Cleanroom Laundry

Monitoring the Laundry cleanroom in which the decontamination process takes place is essential for the quality control of the laundry. The Laundy cleanroom is monitored against ISO14644-1.

But there is also a need to measure the efficiency of the decontamination process. Over the past years the Helmke Drum test has become the most applied test method to batch check the decontamination.

A non-destructive particle-counting tumble test designed to measure particles released at 0.5 microns or greater over a tumbling garment, the Helmke drum test is widely used by cleanroom laundries, or garment processors, to determine the efficiency of the cleaning process. The garment is folded and placed in a rotating drum open at one end and rotated at 10 rpm. A Lighthouse Solair 3100 particle counter is used to sample the air within the drum to determine the average particle release rate in particles per minute for particles equal to or greater than 0.3 µm. The particle counts and size spectra are determined at ten-minute intervals during a five-or 10-minute test period. Results are tabulated and analyzed for average, mean and median value as a function of differing size intervals. However, the Helmke Drum Test does not discriminate between particles and fibers and release of contamination from the inside and outside of the garment, unless all garment closures are sealed during the test -- an important requirement when testing laminated barrier garments.


 Average surface of the fabric in the tested garments (size M is used as reference). The numbers of particles are 0,5 μm or larger.