| 摘要 |
A point light source (1) contains a lamp (2), a concave mirror (3), a lens (4) and a shutter (5). A further lens (6) breaks down the beams from the shutter to a parallel bunch which passes the object to be examined. The object can be electrodes (10,11) and between them a burning light arc (12), with gas (13) flowing around the light arc and the electrodes. The object is positioned in a measurement zone (S) formed with the aid of an objective (8) positioned in the lens focal pt., and a photographic film (9). In this way, a shadow picture of the gas flow (13) around the light arc (12) is obtd. Where slip measurement is used, the objective (8) is replaced by a device (14) with an edge (15). The edge is so adjusted that half the ordinary light beams from the lens (7) are screened. In this way a slip picture of the gas flow around the light arc is obtd. |
