By passing saliva sample thru 130nm filter to remove particles larger than 120nm covid 19 virus particles and concentrating resulting fluid to very small 1 mm2 area of 80nm filter. Pores in this small area of 80nm filter should be clogged up fast raising filter air resistance. Due to high virus density 5.2 log10 ml infected person should clogg filter much faster than healthy person. Time to deflate baloon filed by infected person should be measurably slower.
fluid variant using just common soda bottle and gravity and measuring time for 2L of fluid with infected saliva to pass thru both filters
