SENTINEL is a premium-quality accelerograph that was conceived for strong motion and structural monitoring with budget-sensitive constraints.


The onboard MEMS triaxial accelerometer is synchronously sampled up to 1000 sps at a resolution of 20 bit (or 24 bit SENTINEL-X) and exhibits a dynamic range > 85dB (or > 110 db SENTINEL-X) and a self-noise < 18µg/√Hz.

The integrated memory bank (32 ÷ 256 GB) allows you to manage a ring-buffer for long continuous recordings as well as event data.

The data format is MiniSEED.

The system implements sophisticated trigger criteria (STA/LTA and threshold) that distinguishes false events (i.e. environment vibrations) from true seismic events.

The internal GNSS receiver allows you to create a network where all the instruments are synchronized with the absolute time.


You can control SENTINEL locally via network connection (LAN or WiFi), and remotely using the integrated 4G modem (optional). The instrument can be used as a “stand-alone” unit to record seismic events in the field or it can be used in a MASTER-SLAVE based monitoring network where multiple instruments are connected to each other; SENTINEL is compatible with both the Triton and Atlas and this can be useful when a superior dynamics are needed, for example, as a near field unit.

Thanks to SeedLink protocol SENTINEL is compatible with most popular seismic analysis software (Seiscomp3, Antelope, Earthworm).


SENTINEL is powered by an external DC source (5 ÷ 16 Vdc) and it is equipped with its own internal battery (LiPo) which can guarantee an autonomy of 5 hours in case of a blackout. The battery is a standard 18650 and can easily be replaced. The internal HSPA modem (optional) is backed up by the internal battery.


SENTINEL can be equipped (optional) with 3 relays output and used as a seismic switch, to shut down sensitive equipment such as elevators, pumps, gas valve or to drive alarm systems like sirens or lights.

The instrument comes in an anodized aluminum case which is rugged and shock-resistant and thus suitable for field applications. SENTINEL is designed with an adjustable mounting plate in order to simplify the instrument leveling.

Structural health monitoring is one of the main applications of SENTINEL, with tall buildings, where heavy oscillations excite the structure and the amplitude of physical signals is considerable, SENTINEL performs well even if its dynamic range cannot compete with that of TRITON’s.

In a scenario like this, the only high dynamic (and thus more expensive) accelerograph is placed on the ground floor, where the oscillations of the structure are negligible.

SENTINEL and TRITON can be interfaced and controlled using QUAKELOGIC's Structural Health Monitoring software.

A real-time report of the building and a post-earthquake evaluation of the structural damage can be locally displayed or trasmitted remotely.

The good performance/price ratio makes SENTINEL the ideal choice when building a distributed system aimed at creating an array of seismic data.

Earthquake early warning (EEW) concept is the rapid detection of earthquakes and the alerting of people to shaking.

SENTINEL can detect the non-damaging P-waves and transmit the information about tremors to an alarm center or directly to predefined users before the most damaging S-waves arrive.

SENTINEL is currently used for an ongoing project with the INGV (National Institute of Geophysics and Volcanology) which is experimenting with AI algorithms to detect the earthquake autonomously and quickly.

SENTINEL would be an excelent solution for deactivating sensitive electronic devices when a seismic event is detected, closing gas valves or warning people.

You can have TRITON configured according to your needs

  • WiFi 2.4Ghz comunication radio module.

    Thanks to the SoftAP function you can download data and configure your TRITON directly from your device (mobile, tablet, notebook), moreover you can create a network of completly wireless Lunitek devices.

  • HSPA comunication radio module.

    Insert a standard sim card inside your Triton and you can reach it remotely using a VPN.

  • Carrying handle, useful when using the instrument for dynamic tests, it makes transport easier.
  • TRITON is available with a professional carrying case.

TRITON Velocigraph models available

  • Triton V: High Resolution Recorder combined with 4.5Hz or 2Hz high quality geophones​
  • Triton 1s: High Resolution Recorder combined with 4.5Hz high quality geophones and ad-hoc electronics to extend low frequency sensitivity down to 1s.​
  • Triton 30s: High Resolution Recorder combined with broadband seismometer. Response 30s -100Hz​.​​
  • Triton 60s: High Resolution Recorder combined with broadband seismometer. Response 60s -100Hz​​.​​
  • Triton 120s: High Resolution Recorder combined with broadband seismometer. Response 120s -100Hz​.​​

Models are available in Triaxial, Biaxial or Monoaxial version

Inputs Differential
Channels 3 low noise 24bit
Dynamic Range >136dB@100Sps
Sampling Rate 10,100,200,250,500,1000 Sps
Sampling Topology Synchronous
Data Format MiniSeed or Proprietary
Trigger STA/LTA
Timing Built-in GNSS receiver
Timestamp Encapsulated in data
LAN 10/100 ethernet port
WiFi Optional built-in
Cellular Modem Optional built-in
Power Supply 9-28Vdc – power consumption < 2W
Back up Battery Internal LiPo
System Autonomy w/o external supply 33 hours
Configuration Web Interface
Compatibility Earthworm,Antelope,Geopsy,SeiscomP and SeisGram2K
Weight 2Kg
IP protection IP68
Temperature Range -40°C to +70°C

* LiPo batteries can be discharged between -20°C to +70°C.
LiPo batteries can be charged between 0°C to +45C°.
If temperature exceeds these limits, the charging process is suspended.