TRILLIUM 120 OBS OCEAN BOTTOM SEISMOMETER
Last-Release：2024-04-03 11:24:58 Font Size：T|T
The Trillium 120 Ocean Bottom Seismometer (OBS) combines exceptionally high-performance with low-power to optimize the data collection and duration of ocean bottom experiments. Providing new opportunities for OBS deployments, the Trillium 120 OBS delivers observatory grade performance with the ease-of-use and durability of our industry-leading, land-based Trillium seismometers.
The Trillium 120 OBS is optimized for use with our purpose-built, Pegasus OBS digital recorder, providing a low-power system for integration into any OBS system or as part of our turnkey Abalones Ocean Bottom System.
The Abalones combines a Trillium OBS seismometer with the streamlined workflows of the modern Pegasus OBS digital recorder and a robust deployment frame design, licensed from Scripps Institution of Oceanography.
Purpose-Built for Ocean Bottom Seismology
Incorporating a robust leveling gimbal, the 120 OBS can self-level up to a ± 50° tilt range to ensure a successful deployment on the ocean bottom. The titanium ellipsoidal pressure vessel is rated for 6000 m deployments, and features proven glass epoxy connectors to provide exceptional ruggedness and resistance to corrosion in both marine and fresh water environments.
Ultra Low-Noise Floor in a Versatile Form Factor
The Trillium 120 OBS provides the same exceptionally low-noise performance as our previous Trillium 240 OBS with a 60-70% reduction in size, weight, and power to facilitate integration into new or existing OBS deployment systems.
Low-Power Solutions for OBS Systems
The Abalones combines a Trillium OBS seismometer with the streamlined workflows of the modern Pegasus OBS digital recorder and a robust deployment frame design, licensed from Scripps Institution of Oceanography.
Key Benefits
• Ultra-low 250 mW power consumption reduces battery costs and extends experiment durations
• Maintenance-free titanium pressure vessel rated to 6000 m depths
• Robust design doesn’t require a mass or gimbal lock providing reliable, trouble-free operation
• Precise, kinematic auto-leveling gimbal ensures successful deployments
• Plug and play interface for Pegasus OBS providing automatic generation of StationXML metadata
• Comprehensive State-of-Health logging includes case orientation, providing a powerful data set for optimizing deployments
• Digital connectivity provides visibility into the configuration and State-of-Health prior to deployment
• Also available: Trillium Compact OBS, Trillium 360 OBS
TECHNICAL SPECIFICATIONS TRILLIUM 120 OBS
SEISMOMETER
SEISMOMETER TECHNOLOGY
Topology: Symmetric triaxial
Feedback: Force balance with capacitive displacement transducer
Mass Centering: Motorized recentering automatically initiated during leveling sequence
SEISMOMETER PERFORMANCE
Self-Noise: See self-noise graph
Nominal Sensitivity: 1200 V-s/m (reference user guide for precise value)
Precision: ±0.5% relative to user guide specification
Bandwidth: -3 dB points at 120 s and 150 Hz
Clip level: 16.6 mm/s up to 10 Hz and 0.12 g above 10 Hz
Dynamic Range: 167 dB @ 1 Hz
Temperature: ±45°C without recentering
Magnetic sensitivity: <0.03 (m/s²)/T
AVAILABLE MODELS
T120-OBST2: 6000 m, Titanium Model
LEVELING AND ORIENTATION
Technology: Dual degree-of-freedom motorized gimbals
• Jam-free mechanism, no mass lock/unlock
• Kinematic design preserves full seismometer performance
Range: ±50° tilt range
Accuracy: Levels to within ± 0.5° of true vertical
Leveling initiation: Leveling checks done at
some or all of:
• Configurable delay after power on
• Configurable periodic (three stage user-configurable schedule)
• On external command via serial interface from a SLIP-enabled device or Centaur digital recorder
• Initiated by the digitizer via control line
SELF-NOISE GRAPH
CONNECTORS/PLUGS
Main:
• 16-pin submersible connector male, MCBH16MTI (Titanium)
• Mounted on top of case Vacuum/pressure port:
• 1⁄4-inch male quick disconnect with shutoff
• Vent for evacuation and servicing
POWER
Supply voltage: 9 to 36 VDC isolated
Power Consumption: 250 mW typical quiescent
Protection: Reverse-voltage and over-voltage protected
• Self-resetting over-current protection
• Unit can be powered on for descent and ascent
PHYSICAL
Enclosure: Titanium ellipsoidal pressure vessel, split dual half-shell assembly, with tripod feet
• All connectors on top side
• Dual O-ring sealing between half-shells
• Internal magnetic shield
Diameter: 327 mm
Height: 265 mm (not including tripod, feet,or connectors)
• 340 mm with Abalones tripod kit
Weight:
• Weight of complete assembly in air: 26.1 kg
• Weight of complete assembly in sea water: 10.5 kg
ENVIRONMENTAL
Operating Temperature: -20°C to +50°C
Storage Temperature: -40°C to +70°C
Shock: 20 g half sine, 5 ms without damage, 6 axes
Ingress Protection: Marine 6000 m submersion depth in fresh or salt water
DIGITAL COMMAND AND CONTROL INTERFACE
USER INTERFACE
Web Browser: Onboard web server, accessed with industry standard web browsers using Serial Line IP (SLIP) HTTP
Plug-and-Play: Nanometrics interface for communication via Pegasus OBS digital recorder
CONFIGURATION AND CONTROL
CONFIGURATION AND CONTROL
Sensor: XYZ/UVW mode
• Calibration enable
• Short/long period mode
Leveling: Initiate immediate leveling check
• Automatic cycle mode selection:(post power-on, three stage periodic)
• Automatic cycle parameter selection:(delay and interval times, max attempts)
Unit: Firmware updates
• State-of-health request
DATA OUTPUTS
On-Request: Seismometer mass position values
• Temperature
• Internal relative humidity
• Instrument serial number, subassembly revisions
• Firmware revision
• Case orientation (with respect to vertical)
• Seismometer orientation (with respect to vertical)
• Download logged state-of-health
• Erase state-of-health log
Leveling Log: Every leveling event logged in non-volatile memory
• Full before-and-after State of Health logged
State of Health Log:Recording capacity of >2 years of daily scheduled interval SoH values
• Time from power on
• Seismometer mass positions
• Vessel and seismometer orientations
• Temperature
