9 SCIENTIFIC INSTRUMENTS USED IN THE GEOPHYSICAL-GEOLOGICAL FIELDS-NAMELY, ACCELEROGRAPHS, SEISMIC SENSING, ACCELEROMETERS, SEISMIC TRIGGERS, VIBRATION SURVEY SYSTEMS, TILTMETERS, SEISMOSCOPES, EARTHQUAKE AND VIBRATION MONITORS; SEISMIC SWITCH ACCESSORY PANELS; RECORDING AND PLAYBACK SYSTEMS, DIGITAL DATA ACQUISITION SYSTEMS UTILIZING COMPUTER COMPATIBLE TAPES, MULTI-CHANNEL PHOTOGRAPHIC RECORDING SYSTEMS; SIGNAL CONDITIONERS, GALVANOMETERS, AMPLIFIER FILTERS, DIGITAL TIMING SYSTEMS, TIME AND FREQUENCY RECEIVERS, ANTENNAS, RECEIVER CIRCUIT BOARDS AND RECEIVERS AND FREQUENCY RECEIVERS AND FREQUENCY COMPARATORS, MOTOR SHAKE TABLES AND INSTRUMENT HOUSINGS