REF TEK

ELECTRONIC EQUIPMENT FOR USE IN GEOPHYSICS, NAMELY: [ ANALOG AND DIGITAL SONOBOUYS, ] HYDROPHONES, [ ANALOG AND DIGITAL RECEIVERS, TRANSCEIVERS, PREAMPLIFIERS, ] POWER SUPPLIES, DIGITAL TRANSMITTERS, DIGITAL RECEIVERS, REMOTE DIGITIZERS, DIGITAL FIELD RECORDERS, [ SEISMIC GUN DEPTH CALIBRATORS, WELL LOG RECORDERS, SEISMIC GUN CONTROLLERS AND MONITORS, ] MICROSEISMIC REMOTE RELAY STATIONS, MICROSEISMIC RECORDERS, [ SEISMIC GUN FIRING SENSORS, ] BAND PASS FILTERS [ , SEISMIC GUN FIRING APPARATUS, VSP (VERTICAL SEISMIC PROFILING) GUN TRANSCEIVERS, VSP (VERTICLE SEISMIC PROFILING) REMOTE GUN FIRING UNITS AND TELEMETRY CONTROL COMPUTERS ]