Section 18 Optical, photographic, cinematographic, measuring, checking, precision, medical or surgical instruments and apparatus; clocks and watches; musical instruments; parts and accessories thereof 90 Optical, photographic, cinematographic, measuring, checking, precision, medical or surgical instruments and apparatus; parts and accessories thereof 90 27 Instruments and apparatus for physical or chemical analysis, etc 90 27 20 Chromatographs and electrophoresis instruments Commodity Code Description 90 27 20 00 Chromatographs and electrophoresis instruments