An optical system for a spectrophotometer.

摘要

The system is provided with a first branch (10, 12) and a second branch (14) which receive light from a sample and reference target respectively. A shutter (22) sequentially allows light from the two branches to pass to a mirror (20) having a slit (30), reflective portions (32) and transparent portions (34). Light from the first branch passes througn portions (30) and (34) to a detecting branch (42, 46, 50-56) and some light is reflected through a lens (16) to eye piece (19). Similarly some light from the second branch passes through mirror (30) and (34) to eye piece (19) and some light is retlected to the detecting branch. Acccrdingly the measuring field can be accurately identified by looking through the eye piece (19) whilst at the same time light is airected to the detecting branch for analysis.