| Company | Location |
|---|---|
| Particle Measuring Systems | Boulder, Colorado, United States |
| Particle Sciences | Bethlehem, Pennsylvania, United States |
| Particle Sizing Systems | Port Richey, Florida, United States |
| Particle Technology Labs, Ltd. | Downers Grove, Illinois, United States |
| Particular GmbH | Hannover, Germany |
| Pasture Pharma | Singapore, Singapore |
| Paul Scherrer Institut | Villigen PSI, Switzerland |
| Paul Unger NBS Search Inc. | McLean, Virginia, United States |
| PCB Piezotronics, Inc. | Depew, New York, United States |
| PCN Technology | San Diego, California, United States |
