It took a couple of modifications but the cleanroom has achieved operational status. In order to qualify, we need to have less than 352,000 particles larger than 0.5 microns. We also must have less than 2,930 particles larger than 5 microns. Those numbers are per cubic meter. Our device measures in 0.01 cubic feet. To get the particle count, we multiply the number on the screen by 100 and then again by 35. So the 88 becomes 8800 multiplied again gives us 308,000 particles per cubic meter. That is a nice comfortable margin to work with.

Particle Count

The air monitor showing the values in the cleanroom.

The other number on the device actually measures particles above 2.5 microns. We have a big zero there. But lets go with a 0.75 just in case. That gives us 2,625 particles above 2.5 microns. Still well within specifications.

The biggest modification was to the air filter. We doubled up two MERV 13 filters, That did the trick. We also sealed everything with a silicone sealant. No air leaks now.

We’re calling this one a success.