168213 ⎘
Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light; Systems specially adapted for particular applications; Investigating the presence of flaws or contamination in moving material, e.g. running paper or textiles characterised by the flaw, defect or object feature examined; Optical defects in or on transparent materials, e.g. distortion, surface flaws in conveyed flat sheet or rod for detecting separately opaque flaws and refracting flaws