ELECTRO

ELECTRICAL PROXIMITY SENSING SYSTEMS AND PARTS THEREOF, INCLUDING CONTROL UNITS, PICKUPS AND CABLES, MAGNETIC PICKUPS AND CABLES, AMPLIFIERS, DYNAMIC ELECTRICAL MICROMETERS, [ VACUUM TUBE AMPLIFIERS AND MAGNETIC DYNAMIC ELECTRICAL MICROMETERS, MEASURING EQUIPMENT, ELECTRICAL APPARATUS FOR MEASURING YOUNG'S MODULES OF ELASTICITY, RECTIFIER-TYPE, AND PARTS WHICH MAY BE ASSEMBLED INTO RECTIFIER-TYPE DIRECT CURRENT POWER SUPPLIES ]