| 356 / | HD | OPTICS: MEASURING AND TESTING |
| 955 | DD | MEASURING LINEAR OR ANGULAR SPEED UTILIZING DEVICES CHARACTERIZED BY THE USE OF OPTICAL MEANS, E.G., USING INFRA-RED, VISIBLE, OR ULTRA-VIOLET LIGHT (GO1P 3/36) {3} |
| 957 | | .~ Using diffraction of light (GO1P 3/36C) |