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 26 Instruments and apparatus for measuring or checking the flow, level, pressure or 90 26 10 90 26 10 00 Commodity Code Description 90 26 10 00 00 - For measuring or checking the flow or level of liquids 90 26 20 00 00 - For measuring or checking pressure 90 26 80 00 00 - Other instruments or apparatus 90 26 90 00 00 - Parts and accessories