A Short-Period Vertical Seismometer and Auxiliary Equipment for Installation in Boreholes

Abstract

A new short-period borehole seismometer TBSC6 designed and produced at the Dukhov All-Russian Scientific Research Institute on Automatics provides proportional transformation of vertical seismic velocity oscillation to electrical signal. The seismometer has been designed for installation in boreholes with an inner diamter of 145–220 mm and inclination up to 3.5°. In its technical features (frequency range 0.5–100 Hz, linearity less than 0.006%, noise level less then –10 dB of the low seismic noise model, dynamic range greater than 145 dB, temperature range –25 to 50°C), the seismometer corresponds with the best short-period borehole seismometers in the world. The features achieved make it possible to use the short-period borehole seismometer for seismological observations of both far and local seismic sources and also for seismic situation monitoring in the vicinity of hydrotechnical structures, nuclear power plants, etc.. Auxiliary equipment (locking device, installation complex set with the borehole ahead) provides seismometer installation in boreholes with an inner diameter 145–220 mm at depth down to 100 m. Borehole ahead saves borehole tube with an outer diameter of 150–250 mm.