Abstract:
A mirror (20) for a spectrophotometer has a slit (30), reflective portions (32) and transparent portions (34). When the mirror is illuminated from one side, light passes through the slit (30) and transparent portions (34) to a first location, and some light is reflected by the portions (32) to a second location. Similarly, when the mirror is illuminated from the other side, some light passes through the slit (30) and transparent portions (34) to the second location, and some light is reflected by the portions (32) to the first location.
Abstract:
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 through 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 reflected to the detecting branch. Accordingly the measunngfield can be accurately identified by looking through the eye piece (19) whilst at the same time light is directed to the detecting branch for analysis.