摘要 |
<p>An apparatus (34) for measuring the velocity of a droplet a liquid includes a laser (36) for generating a beam of light into the shape of a thin sheet. A beam divider (40) is along the first path (38) of the light for dividing the beam into two separate beams which extends along second (42) and third (44) paths. The second (42) and third (44) paths lie in a common plane. Along the second (42) and third (44) paths is a device (60) for projecting a droplet of liquid across the second (42) and third paths (44) so that the droplet passes through both of the divided beams. At least one photodetector (52, 54) is along both the second (42) and third paths (44) to receive the divided beams and provide an electrical signal corresponding to the beams. A beam divider (40) which is used to divide the beam into two beams includes a body (62) of an optically transparent material having at least two flat front surfaces (68, 70) which are at an angle with respect to each other to form a V having a sharp corner, and at least two flat back surfaces (74, 76) each of which is spaced from and parallel to a separate front surface.</p> |