Section 18 OPTICAL, PHOTOGRAPHIC, CINEMATOGRAPHIC, MEASURING, CHECKING, PRECISION , MEDICAL OR SURGICAL INSTRUMENTS AND APPARATUS; CLOCKS AND WATCHES; M USICAL INSTRUMENTS; PARTS AND ACCESSORIES THEREOF 90 Optical, photographic, cinematographic measuring, checking, precision, medical o 90 27 Instruments and apparatus for physical or chemical analysis (for example, polari Commodity Code Description 90 27 10 90 27 20 90 27 30 90 27 50 90 27 80 90 27 81 Mass spectrometers 90 27 89 Other 90 27 90