ALPHA Borehole

ALPHA Borehole Seismometer

Product Overview

To round out the ALPHA family of seismometers we offer a slim-line borehole instrument designed for deployment in the deepest boreholes. The three ALPHA seismic sensors are stacked on top of each other to provide a three component seismometer. They are packaged in a robust, water proof stainless steel housing. The whole instrument is securely fixed inside the borehole casing by our unique, completely newly designed single jaw hole lock. In addition we offer the option to add three SIGMA accelerometer sensors to the package. That combination makes this instrument a cost effective multifunction seismic borehole observatory. Several of these six component borehole seismometers were recently deployed in Turkey.
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ALPHA Borehole Seismometer

Key Features

- Rugged housing made from 316 stainless steel material.

- Weight 26.5 kg.

- Dimensions: Slim design diameter of 89 mm

- Waterproof as per IP68 standard.

- Three ALPHA sensors stacked on top of each other

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

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

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

- Power consumption 730 mW at 12 V, 230 mW at 36 V.

- Input power is protected against reversed polarity.

- Doubled nested feed back loop.

- The whole electronic circuitry is two stage galvanically isolated.

- Protection against power transients

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

- Pressure rated to a water depth of 900 meters.

- One jaw hole lock (see photo immediate right).

Single Jaw holelock

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]