I don't see how the sucking capacity of a vacuum would be measured in units of length.
30in is 762000 microns of vacuum
If your talking about vacuum 500 microns of Hg is lower.
vacuum is measured in pressure. To get a vacuum you need a negative pressure. that would be inches of mercury hg
109 microns 1.000.000.000 microns
To suck-in dirt.
1mm is 1000 microns
I assume you mean, how many microns in 0.0015mm. Well there are 1000 microns in a millimetre. In order to convert mm to microns, you have to multiply by 1000. 0.0015mmx1000 is 1.5 microns.