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 22 Apparatus based on the use of X-rays or of alpha, beta or gamma radiations, whet Commodity Code Description 90 22 12 90 22 13 90 22 14 90 22 19 90 22 21 90 22 29 90 22 30 90 22 90