The SM1500 & SM550 Strong Motion Acceleration Sensors (Accelerometers)

  • 3 axis accelerometers
  • Ultra low power consumption
  • Surface/wall mounting
  • MEMS (Force balance/ASIC technology)
  • DC – 750 Hz
  • Wide Dynamic Range 96 dB
  • Output range +/-2 g to +/-12 g linear
  • Noise level 6 ugrms/sqrt (Hz)
  • Operating temperature -20 to +70°C
  • Borehole type (optional)
  • 4 – 20 mA current loop output – NEW!

The SM550 and SM1500 are two MEMS type, three component, acceleration sensors. Both have wide frequency response. The SM1500 model provides response from DC to 750 Hz, while the SM550 model provides response DC to 50 Hz. Many output ranges are available for both models: +/-2 g, +/-4 g, +/-5 g, +/-6 g, +/-10 g, +/-12 g. Default sensitivity is 2.4 V/g for the SM1500, and 1.2 V/g for the SM550.

The SM1500 and SM550 accelerometer technology is based on a variable capacitor transducer, and a feedback circuit that operates in a closed-loop configuration. The feedback force is controlled by an application specific integrated circuit (ASIC) which provides high reliability and low output noise.

The SM1500 and SM550 sensors operate from a 12 V DC power supply that can range from 9 V DC to 18 V DC. The typical power consumption is 33 mA.

Acceleration output is differential analog, swinging between +/-5 V. Other output voltages are available.

4 – 20 mA current loop output is also available for both sensors

The default cable length between the sensor and the digitizer is approximately 2 meters but it can be extended. The 2 – 40 mA version can have a long connection cable.

The sensors are surface mounted or wall mounted over a provided adjustable base, giving the ability for leveling and orientation.

Seismic accelerometers can be used for early warning systems’ implementation.

Contact ISTI to discuss your application requirements.


The GEOtinyAC! compact digital accelerograph

GEOtinyAcc is a compact, miniature, digital accelerograph which integrates three acceleration channels. Actually, it is a GEOtiny! seismometer equipped with an acceleration sensor. It supports a high resolution 24 bit digitizer (optional 32 bit A DC), embedded linux OS, and GPS or NTP timing. A SeedLink server ensures reliable, real time data telemetry while large storage volume ensures long period, local data recording. The instrument has very low power consumption so it can be powered from a small 12 V DC battery.

Design simplicity is a great advantage and it is reflected in the price, which is only a fraction of the price of common commercial accelerographs. The sensor delivers superior signal to noise ratio and broadband response. The accelerograph communicates through an Ethernet CAT5 connection or through a wifi connection. The user has to just plug in and connect with the unit. The device is compliant with the Los Angeles building code.

  • 3 axis accelerometers
  • Ultra low power consumption
  • Only 130 mm D/76 mm H
  • MEMS (Force balance / ASIC technology)
  • DC – 750 Hz, wide dynamic range 96 dB
  • Output range +/-2 g to +/-12 g linear
  • Noise level 6 ugrms/sqrt (Hz)
  • Integrated 24 bit digitizer, miniSEED data format
  • Local storage, and/or telemetry
  • Integrated SeedLink and Earthworm servers
  • Web interface, SSH, FTP, SFTP
  • Operating temperature -20 to +70°C
  • Aluminum IP68 case

This device is compliant with the Los Angeles building code.

GEOwarning, Early warning accelerograph

GEOwarning is a compact, ultra low cost, digital accelerograph. It integrates 3 axes, a MEMS accelerometer, a 20 bit digitizer, embedded linux OS, and GPS or NTP timing. SeedLink and Earthworm servers ensure reliable, real time data telemetry while large storage volume ensures a long period of local data recording. The instrument has very low power consumption so it can operate powered from a small 12 V DC battery. Due to its small size and its flexibility for communication protocol (Ethernet or WiFi) and for timing (GPS or NTP), it can easily be installed at buildings and other structures. The device supports a software configurable, variable range of +/-2 g, +/-4 g, +/-8 g, presenting an ideal solution for a wide range of structural monitoring and early warning applications. Minimum data latency, along with the calculation of an earthquake’s Cumulative Absolute Velocity (CAV), guarantee that the user can be immediately alerted at the beginning of an event. Compact design is a competitive advantage and this is reflected in the price, which is only a small fraction of the typical commercial accelerograph’s cost. The user is now able to deploy five times more units for the same budget.

  • 3 component, miniature accelerograph
  • Range +/-2 g, +/-4 g, +/-8 g
  • Low power consumption
  • Ethernet and WiFi
  • Dimensions 90 X 115 X 55 mm
  • 20 bit analog to digital converter
  • Embedded SeedLink and Earthworm Server
  • Real time telemetry and local storage
  • MiniSEED data format
  • Linux OS
  • Web configuration interface
  • SSH, SFTP,HTTP NTP
  • SPDT relay, software configurable
  • Dynamic Range 85 dB
  • STA/LTA, PGA, CAV
  • Operation Range: -20 +70°C
  • Waterproof IP67 Aluminum Case

GEOwarning