DIY Bubble Point testing of filter media
A colleague has been working with a group in South Africa sewing cloth masks from fabric of unknown provenance. It's far from ideal, but they're making do with what they have. They're unsure how best to determine which fabrics are adequate.
Bubble point testing is a pretty well established method of evaluating membrane porosity. I'm curious if the technique could be applicable for mask filters. If so, could this be an avenue for an ultra low cost filter test?
My quick thought for something that could be done at home was:
- Take two empty soda bottles and fill one with water.
- Print an adapter that joins the two and can hold a piece of fabric between them.
- Start setting weights on top of the air bottle until you observe bubbles forming on the water side.
- We would need to correlate those weights against known filtration media, but they should give us an indication of porosity.
Does this sound like an idea worth exploring?