ELECTRO-TECH

HYDROPHONES, SEISMOMETERS, GALVANOMETERS, OSCILLOGRAPHS, PHOTOGRAPHIC DEVELOPING UNITS COMPRISING A COMPACT CASE WITH SOLUTION CANS AND LIGHT-PROOF HOODS, ELECTRONIC TESTING INSTRUMENTS TO EVALUATE THE TRANSIENT CHARACTERISTICS OF ELECTRONIC EQUIPMENT, CALIBRATED INSTRUMENTS TO SIMULATE LABORATORY CONDITIONS FOR LABORATORY MEASUREMENTS, AND METAL HOUSINGS, CASINGS AND RACKS ADAPTED FOR USE WITH THE AFORESAID INSTRUMENTS