• Symmetric Triaxial Seismometers by Bruce Townsend

    | Article

    The first modern broadband seismometer to be based on a Galperin configuration was the Streckeisen STS-2, an observatory-grade vault instrument introduced in 1990. Nanometrics introduced a symmetric triaxial seismometer with a 240 s lower corner period, the Trillium 240, in 2004. There are now a wide variety of symmetric triaxial seismometers available including models designed for borehole, posthole, ocean bottom, and vault installation and ranging from ultracompact to the large form factors.