| PSC | Description
|
| 6605 | Navigational instruments |
| 6610 | Flight instruments |
| 6615 | Auto pilot mechanisms airborne gyro |
| 6620 | Engine instruments |
| 6625 | Elect electronic measuring instrumt |
| 6630 | Chemical analysis instruments |
| 6635 | Physical properties test eq |
| 6636 | Environmental chambers & related eq |
| 6640 | Laboratory eq & supplies |
| 6645 | Time measuring instruments |
| 6650 | Optical instruments |
| 6655 | Geophysical instruments |
| 6660 | Meteorolog instruments & apparatus |
| 6665 | Hazard-detecting instru & apparatus |
| 6670 | Scales & balances |
| 6675 | Drafting surveying & mapping instru |
| 6680 | Liquid-gas-motion measuring instru |
| 6685 | Pressure temp humidity instruments |
| 6695 | Combination & misc instruments |