In here, we are very limited to access of Portacount. So we often use a method called "Saccharin" to fit test masks. It is to produce steam with saccharin. If the sweet taste of the saccharin is detected, the mask does not fit well enough. In experience, the mask has less than 20-25 fit factor. The method is very very cheap comparing to a Portacount. I wonder is it popular in the US?
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