L&N

ELECTRICAL MEASURING INSTRUMENTS-NAMELY, ELECTRIC METERS AND INDICATORS, GALVANOMETERS, VOLTMETERS, AMMETERS, WHEATSTONE BRIDGES, POTENTIOMETERS, [ PERMEAMETERS, ] INDUCTANCE AND CAPACITY BRIDGES, INDUCTOMETERS, ELECTRIC TESTING SETS, ELECTRIC DECADE SETS, RESISTANCE STANDARDS, INDUCTANCE STANDARDS, CAPACITY STANDARDS, STANDARD CELLS, THERMOCOUPLES, ELECTRIC THERMOMETERS, RESISTANCE THERMOMETERS, PHOTOMETERS, PYROMETERS, CONDUCTIVITY CELLS, ION-CONCENTRATION CELLS; INSTRUMENTS FOR MEASURING AND INDICATING CONDUCTIVITY OF ELECTROLYTES, ION CONCENTRATION, FLOW OF FLUIDS, SPEED, FREQUENCY, AND COMPOSITION OF MIXTURES; GAS ANALYZERS; RECORDERS OF MAGNITUDES OF TEMPERATURE, HUMIDITY, FREQUENCY, SPEED, PRESSURE, CONDUCTIVITY, ION CONCENTRATION, RATE OF FLOW OF FLUIDS, ELECTRIC CURRENT, ELECTRICAL POTENTIALS, ELECTRICAL IMPEDANCE, [ TURBIDITY, ] PHOTO-ELECTRIC EFFECTS, AND COMPOSITION OF MIXTURES; AND RECORDING INSTRUMENTS CONTROLLED BY A MEMBER DEFLECTING IN RESPONSE TO THE MAGNITUDE TO BE RECORDED