Plastics identification

Optical relay with deflectors for analysing samples

An optical relay 10 for an Infra Red spectrometer is disclosed having a housing to be located between the source and detection windows of a spectrometer. The relay 10 comprises a sample window 12 against which a sample may be placed for analysis by the spectrometer. The relay 10 also has a sample holder 14 for introducing a sample into the housing for analysis by the spectrometer. Two systems of deflectors 23,24,26,28 are arranged within the housing for selectively deflecting the IR radiation of the spectrometer to analyse a sample placed against the sample window 12 or a sample introduced into the housing by means of the sample holder 14. The IR radiation may also be directed using concave mirrors 30,36. The apparatus are used in the identification of plastics material.