A new idea in garment testing
To the Editor:
I saw the article on garments [“Methods for testing cleanroom garments,” May 1997, p.17] in the May 1997 issue and find it hard to believe that there still isn`t one test that everyone agrees upon. Let me suggest that the garment be spread over a support with holes and that air from a jet go through it just once. On the downstream side the air is sampled and there is no question of a particle being removed and then redeposited on the next pass.
One thing that wasn`t mentioned is the bacteria, some comes from the wearer, some from the ventilation system (wet spots in air conditioners are “alive”). Why isn`t there a simple system that scans each person as they enter the gowning room from the cleanroom? It would make use of a UV light to cause some of the bacteria to fluoresce. You could get a level of the response with a photocell and say “this garment is clean enough to back into the cleanroom, the next garment is dirty, put it in the laundry basket”.
Anyone who thinks that all the garments are clean on Tuesday, but dirty on Friday has never tested them with a particle counter.
Stuart A. Hoenig, P.E., Ph.D.
University of Arizona