摘要 |
An optical analyser comprises a light source having a plurality of emitters (4a . . . e) selectably energisable by means of control unit (12) and computer (10). A tilting filter arrangement (8) is also provided having a plurality of optical interference filters (20c) say. Each filter is simultaneously tiltable to vary a wavelength of incident light from associated emitter, (4c) say, transmitted there through and along an associated light path (16a . . . e), towards an analysing region (18). |