An inspection system, wherein said inspection system is configured to detect and analyse matter arranged in an inspection area, which inspection system comprises:
- an irradiation arrangement for emitting optical radiation within a first predetermined wavelength range such as UV, VIS, MIR and/or NIR for irradiating said matter, a detector system with at least one detector adapted to receive and detect signature radiation within a second predetermined wavelength range such as UV, VIS, MIR and/or NIR, which signature radiation is optical radiation reflected, scattered and/or emitted by said matter,
- a switching element arranged to be rotatable around a rotation axis between at least one inspection position, at least one dark reference position and at least one white reference position, and
- a white reference target element configured to be irradiated by reference radiation, which reference radiation is optical radiation emitted by said irradiation arrangement
- wherein said switching element comprises a plate, which plate comprises:
- at least one inspection zone each said inspection zone being an opening or window in said plate,
- at least one dark reference zone, each said dark reference zone being an opaque portion of said plate, and
- at least one white reference zone, each said white reference zone comprises an associated reflective element which associated reflective element comprises a reflective surface, which reflective element is arranged such that, in said at least one white reference position of the switching element said reflective surface of the reflective element is irradiated by said reference radiation and redirects said reference radiation towards said detector system and said reflective element blocks said signature radiation from reaching said detector system, and
- wherein said switching element is arranged to be rotatable around said rotation axis such that:
- in each of said at least one inspection position of the switching element, a respective one of said at least one inspection zone transmits said signature radiation towards said detector system,
- in each of said at least one dark reference position of the switching element, a respective one of said at least one dark reference zone blocks all or at least most of the signature radiation from reaching said detector system,
- wherein:
- said white reference target element is further configured to redirect said reference radiation towards said switching element
- said inspection system further comprises an optical arrangement for redirecting said signature radiation towards said switching element before it is transmitted by a respective one of said at least one inspection zone,
- each said white reference zone further comprises an opening or optical window in said plate, and
- in each of said at least one white reference position of the switching element a respective associated reflective element being associated with a respective white reference zone is configured to be irradiated by said signature radiation, and said associated reflective element is configured to block said signature radiation from reaching said detector system, and
- said reflective surface of said respective associated reflective element is configured to be irradiated by said reference radiation after said reference radiation has been redirected by said white reference target element and said reflective surface is configured to redirect said reference radiation towards said opening or optical window of said respective white reference zone and said opening or optical window of said respective white reference zone is configured to transmit said reference radiation towards said detector system.