| 摘要 |
The present invention provides an apparatus and a method for determining sizes of particles in a fluid. Furthermore, it provides a method for determining a number of particles in a fluid and production methods for the apparatus according to the invention. The method for determining sizes of particles in a fluid comprises: a lens optical system (5) having a laser absorption device (10), which absorbs unscattered laser beams (22) emitted by a laser source (20), wherein the laser absorption device (10) is encompassed by a first, second and third lens (41, 42, 43), wherein the first lens (41) directs scattered laser beams (24) onto the second lens (42) and/or the third lens (43), wherein the second lens (42) directs laser beams (26) that impinge on the second lens (42) proceeding from the first lens (41) substantially onto a first photodetector (51), which generates first measurement signals, wherein the third lens (43) directs laser beams (26') that impinge on the third lens (43) proceeding from the first lens (41) substantially onto a second photodetector (52), which generates second measurement signals; and an evaluation device (53), which evaluates the measurement signals of the two photodetectors (51, 52) for determining the sizes of the particles (30). |
