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The S-20 Near Broadband Surface Type Seismic Sensor

S-120 broadband seismic sensor

Overview

The GEO-S120 broadband seismometer relies on years of experience designing high precision, low noise, and reliable seismic equipment. It is based on a very sensitive capacitive transducer that monitors the position of the seismic bass and a feedback loop that generates signal output proportional to velocity with extended bandwidth 120sec to 80Hz. The instrument has low self-noise, which is ideal for local, regional, and teleseismic earthquake recording. No mass lock is required, and it supports automatic mass centering. The sensor provides calibration input and communication via a serial port. The GEO-s120 design is exceptionally versatile, ideal for both direct bury and vault use cases. The seismometer casing is made from hard anodized aluminum or stainless steel.

+ Additional Details

When combined with our GEOthree or GEOsix datalogger, the GEO-S120 provides a true broadband station with low overall power consumption, providing an ideal solution for rapid response applications requiring high-resolution data. The GEO-S60 version of this seismometer has equal specifications, but the output velocity response is flat between 60sec to 90Hz.

+ Features

• Three-component broadband seismometer
• Force Balance with capacitive transducer
• Surface or shallow bury installations
• 150mm diameter, 125mm height
• Aluminium or Stainless Steel casing
• Bandwidth 120sec - 80Hz or 60sec-90Hz
• Sensitivity 1200V/m/s
• Power consumption < 1W
• Automatic mass center
• Self-noise 80sec-16Hz below NLNM
• Dynamic range > 155dB @1Hz
• Operation Range: -20 +60°C

S-120 Broadband Seismic Sensor

The S-20 Near Broadband Surface Type Seismic Sensor

S-20 near broadband seismic sensor

Overview

The S-20 seismometer is a three-component, velocity output, near broadband seismic sensor. The design is based on the electronic velocity feedback applied to a single-coil, low-period geophone. The frequency bandwidth is extended from 50 Hz down to 20sec.

+ Additional Details

Two sensor types are provided: a borehole seismometer and a surface seismometer.

The borehole type is housed in an 80 mm diameter casing, while the surface type unit’s diameter is 130 mm. The cable length is typically 10 meters. It can be extended to 100 meters or more if required.

No mass lock or centering is required, making an easy connection with the digitizer. The settling time of the unit is very short, only one minute. Sensitivity is 1500 V/m/s (differentially), thus providing a very sensitive seismic sensor. A test line is also provided for calibration and testing.

The sensor is ideal for regional earthquake seismology, low-frequency grumbling of volcanoes, and aftershock studies.

+ Features

• Three-axis near broadband response (20 sec – 50 Hz) seismometers
• High sensitivity 1500 V/m/s, low power consumption.
• Borehole type, 80 mm diameter.
• Surface type, 140 mm diameter.
• Typical 20 m cable length, optional up to 150 m
• Built-in test line.