A portable slow motion magnetic tape recorder for geophysical purposes

Abstract

A portable slow motion tape recorder has been developed which will continuously record frequencies between 0 · 0·2 and 15 c/sec for one month at a tape speed of 0–2 mm/sec. Speeds of 0–1 and 0–4 mm/sec are also available. The recorder, which is particularly suitable for seismology, is inexpensive, has high sensitivity and timing accuracy, requires only 2^ watts of battery power, and can operate unattended for long periods.