| PSC | Description
|
| 6605 | Navigational Instruments |
| 6610 | Flight Instruments |
| 6615 | Auto Pilot Mechanisms and Airborne Gyro Components |
| 6620 | Engine Instruments |
| 6625 | Electrical and Electronic Measuring Instruments |
| 6630 | Chemical Analysis Instruments |
| 6635 | Physical Properties Testing and Inspection Equipment |
| 6636 | Environmental Chambers and Related Equipment |
| 6640 | Laboratory Equipment and Supplies |
| 6645 | Time Measuring Instruments |
| 6650 | Optical Instruments |
| 6655 | Geophysical Instruments |
| 6660 | Meteorological Instruments and Apparatus |
| 6665 | Hazard-Detecting Instruments and Apparatus |
| 6670 | Scales and Balances |
| 6675 | Drafting Surveying and Mapping Instruments |
| 6680 | Liquid and Gas Flow, Liquid Level and Mechnical Motion Measuring Instruments |
| 6685 | Pressure, Temperature and Humidity Measuring Instruments |
| 6695 | Combination and Miscellaneous Instruments |