ALPHA Light

ALPHA Light Seismometer

Product Overview

In some instances, a lighter version of a robust three component broadband seismometer is desirable. We can offer such a lighter version in our ALPHA family of instruments by packaging a standard ALPHA surface/vault version into a casing of anodized aluminium instead of stainless steel. The material is as robust and corrosion resistant, but the ALPHA Light seismometer is about 30 percent lighter than the standard version. The performance of the two seismometers is essentially the same, except that the standard ALPHA has a slightly lower intrinsic noise at the lowest frequencies compared to the ALPHA Light. As in the case of the standard version, the ALPHA Light is shielded against magnetic disturbances by a Mu-metal sheet inside its casing.
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ALPHA Light 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.

- Other response options: 0.033 Hz (30 sec) to 150 Hz and 0.0166 Hz (60 sec) 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.

Enclosure

- Rugged housing made from anodized aluminium.

- Weight 10.5 kg.

- Dimensions: outer diameter 16.5 cm, height 28.4 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.

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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References

  • 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]