ALPHA Digital

Digital ALPHA Seismometer

Product Overview

In combining a standard three component ALPHA seismometer with our well proven 24-bit TAU digitizer, this Digital ALPHA is a seismometer with a fully digital output. This two-in-one package eliminates the need for an extrernal digitizer, thereby saving valuable deployment space. It also makes installation extremely easy, as there is no need to handle bulky seismometer cables. In conjunction with our OMEGA control and data acquisition software, this seismometer can be fully remotely controlled and operated.
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Digital ALPHA Seismometer

Key Features

Instrument Design

- Classical orthogonal sensor topology with sensor axes pointing in the three cardinal directions.

- Fine pitched adjustable feet manufactured from phosphor bronze.

- Shielded against external magnetic disturbances by mu-metal inside the casing

- Doubled nested feed back loop.

Instrument Characteristics

- Flat frequency response from 0.008333 Hz (120 seconds) to 150 Hz.

- Offered in a whole range of sensitivities from 2*750 to 2*10,000 V/m/s (differential output)

- Operational range within +/- 5.0 degrees of tilt.

- Cross axis rejection >-75dB.


- Rugged housing made from anodized aluminium.

- Weight 11.5 kg.

- Dimensions: outer diameter 16.5 cm, height 35 cm

- Waterproof as per IP68 standard.

 Power and Electronics

- Power consumption < 1 Watt within the operating range from 9 to 36 Volt.

- Input power is protected against reversed polarity.

- The whole electronic circuitry is two stage galvanically isolated.


 - 24 bit digital output.

- See here for detailed information about the TAU digitizer

To obtain a detailed data sheet for this seismometer, please contact Gaiacode Headquarters

 Disclaimer: The product specifications and the stated data are subject to change without prior notice.

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  • Ref 1 USHER, M.J., BURCH, R.F. and GURALP, C.M., “Wide-band Feedback Seismometers”, 1979. Physics of the Earth and Planetary Interiors, 18: 38-50.
  • Ref 2 M,J, USHER and C.M. Guralp, “The design of miniature wideband seismometer” Geophys. J.R. ast. Soc. (1978)-55 (605-613) ,
  • Ref 3 GURALP, C.M., “The Design of a Three-component Borehole Seismometer”, 1980. Ph.D. Thesis, Univ of Reading.
  • Ref 4 GURALP C.M. Patent Application, No: 7909579 Filed: 19th March 1979 (declaration priority from Appln No: 10279/78 Filed: 15th March 1978) “Vertical Seismometer”.
  • Ref 5 GURALP C.M. United States Patent Application Number: 4,280.206 March 1979. SEISMOMETERS.
  • Ref 6 GURALP C.M. UK Patent Application GB 2-144-287-A. July 1983 Analog-to-digital converters for Seismometers. The National Research Development Corporation (UK)
  • Ref 7 GURALP C.M. UK Patent Application No. 1900719.4; Title: Infrasound Detector [M&S-IRN.FID4315516]