[ EXPERIMENTAL APPARATUS AND INSTRUMENTS, namely, - PHOTOMETERS, THERMOSTATS, HYGROSTATS, TEST TUBES, BEAKERS, FLASKS, LABORATORY DISHES, MORTARS, PESTLES, MEASURING INSTRUMENTS WITH GRADUATIONS IN STANDARD MEASURING UNITS, namely, - RULES, TAPE MEASURES, BALANCES AND SCALES, THERMOMETERS, PLANIMETERS, GAS METERS, WATER METERS, WATER METERS AND SPIROMETERS; ] MEASURING INSTRUMENTS WITH GRADUATIONS IN DERIVED MEASURING UNITS, namely, [ - TACHOMETERS, SPEED METERS, ACCELEROMETERS, PRESSURE METERS, LUMINOFLUX METERS, ILLUMINOMETERS, ] REFRACTOMETERS, [ HYGROMETERS, CALORIMETERS, FLOWMETERS, LEVEL GAUGES, DENISMETERS, CONCENTRATION METERS, GRAVIMETERS, NOISE METERS, ACOUSTIC METERS, VIBRATION GAUGES, DYNAMOMETERS AND SPEED GAUGES FOR SHIPS; ] PRECISION MEASURING MACHINES AND INSTRUMENTS, namely, [ - LENGTH GAUGES, GAUGE COMPARATORS, INTERFEROMETERS, ANGLE DIVIDING MACHINES, CLINOMETERS, ANGLE GAUGES, SCREW THREAD MEASURING MACHINES AND INSTRUMENTS, ] SLIDE PROJECTORS AND MOVIE PROJECTORS, [ SURFACE ROUGHNESS TEESTERS, FLATNESS TESTING MACHINES AND INSTRUMENTS AND STRAIGHTNESS TESTING MACHINES AND INSTRUMENTS; MATERIAL TESTING MACHINES, namely, - METAL HARDNESS TESTING MACHINES, METAL STRENGTH TESTING MACHINES, METAL COMPRESSION TESTING MACHINES, CEMENT TESTING MACHINES, CONCRETE TESTING MACHINES, LUMBER TESTING MACHINES, TEXTILE TESTING MACHINES, RUBBER TESTING MACHINES AND PLASTIC TESTING MACHINES; ] SURVEYING INSTRUMENTS, NAMELY[ - PRECISION THEODOLITES, TRANSITS, SEXTANTS, ALIDATES, LEVELING INSTRUMENTS, DISTANCE MEASURING INSTRUMENTS, PHOTOGRAMMETRIC INSTRUMENTS, GYRO COMPASSES, GYROMAGNETIC COMPASSES, MAGNETIC COMPASSES, ] PROJECTORS [ AND TRIPODS FOR PHOTOGRAPHIC INSTRUMENTS, VIDEO INSTRUMENTS AND SURVEYING INSTRUMENTS; ASTRONOMICAL MEASURING INSTRUMENTS, namely, - ZENITH TELESCOPES, TRANSIT INSTRUMENTS, AND ASTRONOMICAL SPECTROGRAPHS ]