inspection of a sample by a beam of nir radiation that also passes through an object or medium such as a conveyor belt before or after passing through the sample and before being received by a detector it is to be understood that this is possible because certain materials from which a conveyor belt may be fabricated are sufficiently transparent to allow passage of nir radiation therethrough thus embodiments of the invention may be integrated into industrial facilities such as an industrial production line in a more convenient and less intrusive manner furthermore an advantage of nir imaging over x ray imaging is that there is a reduced risk of damage or other unwanted effects on a sample such as a chemical change to an active ingredient of a pharmaceutical it is to be understood that where a detector is located on an opposite side of a conveyor to the article the conveyor belt or other conveyor employed in or with embodiments of the present invention must be formed from a material that allows nir radiation to be transmitted therethrough for example a material that is transparent to nir radiation or a material that is translucent to nir radiation it is to be understood that some embodiments of the invention may employ a fan type.