Types of HEPA filtersAccording to NIOSH (the US National Institute for Occupational Safety and Health), a true HEPA filter is one that can trap 99.97 percent of dust particles that are 0.3 microns in diameter (where a micron is one millionth of a meter). There's nothing particularly ...
Without filters, however, they blow quite a lot of the finer dust (the harmful particles known as PM10s, smaller than 10 microns) back into your room; so, instead of "vacuum cleaning", they are simply "dust rearranging": sucking in dirt and blowing it back out so it settles somewhere ...
Once that's done, it can be electroplated just like a metal. Depending on how much wear and tear the plated part has to withstand, the coating can be anything from about 10–30 microns thick.Why use electroplating?Photo: This car wheel is made from aluminum metal plated with nickel in ...