The improvement of old and the application of new techniques in seismometry

The progress in the development of seismic instrumentation has resulted in state-of-the-art instruments capable of attaining a dynamic range of up to 140 dB in a wide frequency range of 2.5-3 decade. Old seismic instruments have been improved to achieve such an aim. Mechanical parts have been replaced with electronics, thus reducing the cost of instruments. The new instruments are capable of working in a wide range of temperatures. (author)