thanks for the vid, so this shows how well the mask filters particles <0.5um and <2.5um? this means that f740 and f506 doesn't filter <0.5um well since the readings stay at 2k+?
Sort of, just look at the 0.5 microns number, it's a cheap meter, nothing fancy or accurate. You just need a ballpark number to show before/after and also to compare bt masks......which it can easily do esp if the challenge aerosol levels are decently high (that is why sometimes i use a pc of smouldering tissue to get it from say 1.5k -> 9k.
In fact tissue paper or wood smoke is predominantly 0.1 microns plus minus. Cigarette is 0.2 0.3 microns median for eg.
for the charmzone one, why did it hover around 300+ until the detector was shifted? is it because it wasn't sealed well at first?
Good catch. I think so......prob v minor leak at the bottom then, coz i stuck and closed 50% of my air purifier outlet with scotch tape so that the base of my meter rests on it, and also 30% of the the bottom of my meter is with scotch tape also. I think a wee small portion didn't sit well then, so i just shifted it and it went down.
Coz i know this Jangaran/charmzone KF94 will measure well coz before the video i already tested it......and someone else also sent me charmzone stuff before as well.
this shows how sensitive a mask is with leaks, in relation to my meter's readings (which is rather sensitive, just not sensitive/accurate enough for those what 99.xx % conclusion coz anyway my challenge aerosol is ont standardised )
This also gives an idea to us how important the fit of the mask is, and how important it is to use a good surgical tape (ie 3M micropore, v sticky.....tho i guess many hate this).
The mask to be tested would sit between the AP outlet and meter's bottom inlet hole. The meter's both sides are taped up, leaving only a small hole at the top for it to exhaust. the laser particle counter module is the silver one, with the black coloured sampling inlet visible. (around 90 deg perpendicular to the incoming filtered air)
