SIGMA Digital

SIGMA Digital

Product Overview

In combining a standard three component SIGMA accelerometer with our well proven 24-bit TAU digitizer, this Digital SIMGA is an accelerometer 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 accelerometer can be fully remotely controlled and operated. Three available user interfaces (10/100 Base-ehternet, USB and Serial RS232) makes communication with this instrument easy and reliable.
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SIGMA Digital

Key Features

Instrument Design

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

- Fine pitched adjustable feet manufactured from brass.

- All sensor components are made of non-magnetic materials, minimizing noise induced by outside magntic fields.

- Single slotted base fixing point

Instrument Characteristics

- Flat frequency response from DC to 400 Hz.

- Four remotely configurable saturation levels between +/- 4g and +/- 0.5g.

- Other options down to +/- 0.05 g available.

- Dynamic range at +/- 2g >170 dB, at +/- 4g >167 dB

- Operational range within +/- 10.0 degrees of tilt.

- Cross axis rejection >-70 dB.

- Operating temperature range: -20 to 75 deg C.


- Rugged housing made from hard anodized aluminium.

- Weight 2.45 or 2.75 kg, depending on connector.

- Dimensions: outer diameter 14 cm, height 16.5 cm or 18 cm, depending on connector.

- Waterproof as per IP68 standard.

 Power and Electronics

- Power consumption < 2.1 W

- Power operating range from 9 to 36 Volt.

- The sensor's electronic circuitry is galvanically isolated, protected against polarity switch and voltage transients.


 - 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]