Optical analytical instrument.

摘要

An analytical instrument includes an optical system having a source of incoming radiation (11) which in a transmission test is focused by a primary focusing element (15) onto a sample (16). The radiation transmitted through the sample is collimated by a focusing-collimating element (20) and directed across the beam of incoming radiation (14) before being focused on a detector (12). To perform a test of the reflectance of the sample, an intercept element (28) is moved into position in the incoming beam (14) to deflect a portion (36) of the beam which is directed to the focusing-collimating element (20) and focused on the sample. The reflected radiation from the sample is collected by the focusing-collimating element (20) into a collimated beam (38) that is parallel and adjacent to the incoming beam, and which is directed in a path which passes by the intercept element (28) to be focused onto the detector (12). By selectively moving the intercept element (28) into and out of the path of the beam (14), a sample may be analyzed for both transmission and reflectance characteristics without moving the sample.