Portable refraction seismograph and field service unit used for setting all recording parameters, retrieving seismograph memory plus analysis and display of data in the field. A basic field service unit includes a portable computer, printer, and satellite-tuned clock. It serves up to 30 portable refraction seismograph instruments.

Refraction surveys tend to be big affairs, requiring many instruments and many people to deploy them. For example, during the 1993 refraction experiment in the Trans-Hudson Orogen, 525 individual portable seismographs were deployed over a total length of 2,000 km along three individual lines to record more than 40 separate shots by a crew of 55 persons using 30 trucks, 2 helicopters and railway cars.