After choosing the monitoring method, determine how many monitoring locations or particle counters you need. If the area of your cleanroom is 1,000 m² or less, use Table A.1 provided in ISO 14644-1:2015. If your area is greater than 1,000 m², first divide the cleanroom area (in m²) by 1,000. Then multiply this number by 27. Remember that this is the minimum number of locations. You can always have more to cover additional critical locations.

For example, a typical cleanroom area of 9290 m² (100,000 ft²) would have 251 monitoring locations required by ISO. We recommend even distribution and mounting at a work height of 76 cm (30 in).

9290 / 1000 = 9.29 x 27 = 251

Keep in mind the ISO 14644-1:2015 standard only applies to cleanroom certification. Cleanroom operators should evaluate their processes and the sensitivity of their product to contamination to determine the number of sampling locations required. Our advice is to monitor where it counts. Measure where your product is exposed and where contamination will cause damage. The focus should be on where the risk is the highest.

A solution for monitoring a few locations frequently while keeping the option of portability is the Lasair® Pro Aerosol Particle Counter. For dedicated, continuous sampling of one location where space is a concern, consider the Airnet® II Air Particle Sensor.

Want to read more about Selecting an Airborne Particle Counter? Jump to other released posts in this series:

Part 1 of 4: Terminology and Standards

Part 2 of 4: Types of Monitoring

Part 4 of 4: Particles in Process Gasses

 

Learn more… Get the full paper here.