| 摘要 |
1,019,494. Optical apparatus. FRITZ HELLIGE & CO. G.m.b.H. April 20, 1964 [April 19, 1963], No. 16376/64. Heading G2J. Rectangular glass precision vessels for holding samples of liquid for calorimetric or other optical investigations are manufactured by spacing two plane parallel plates 6a, 6b, which in use are at right angles to the direction D of the rays of light 8, an accurate distance apart by means of one or more gauges and cementing their edges to two glass plates 6c, 6d, which in use are parallel to the direction D so that the layers of cement 7 are also parallel to direction D. Thus the variable thickness of cement layers 7 does not alter the accurate spacing of plates 6a, 6b. The plates 6c, 6d may be of frosted glass so that the orientation of the vessel in an optical device is readily apparent. |
