Trillium Posthole Broadband Seismometer


Ideally suited to uncased, buried installations, the Trillium Posthole (PH) is housed in a stainless steel enclosure incorporating a high-pressure, marine grade connector. Its down-hole includes a 5.6 inch diameter casing and a centered attachment eye bolt on the top surface.

Low power consumption of 560mw minimizes power source requirements at the site.

An advanced, internal leveling system allows the unit to operate over a tilt range of +/-5 degrees (+/-10 degrees is also an option). The axis stack is mechanically leveled to ensure that the vertical axis does not couple horizontal noise.

It has a response flat to velocity from 120 seconds to 150 Hz and a self noise below the NLNM at 100 seconds.

Nanometrics’ Trillium Posthole seismometer might be right for you if:

  • You’re doing local, regional or teleseismic studies
  • You need a robust, waterproof, stainless steel enclosure to protect the sensor from hostile environments
  • You’re looking for the low power consumption, remote mass centering and robust no-mass lock design inherent in all Trillium seismometers
  • Specifications

    Specifications are subject to change without notice.

    Topology Symmetric triaxial
    Feedback Force balance with capacitive transducer
    Self-levelling Internal automated levelling with ±5° (±10° optional)
    Levelling initiation Control line or serial port command
    Mass centering Motorized re-centering automatically initiated during levelling sequence
    Alignment N-S line on cover for downhole sighting
    Keying features for downhole alignment rod
    N-S marks on base for pier installation
    Self-noise See plot under 'Performance' tab
    Sensitivity 1200V-s/m ±0.5% precision
    Bandwidth -3 dB points at 120 s and 150 Hz
    Clip level >16.6 mm/s up to 10 Hz and 0.17 g above 10 Hz
    Temperature ±45°C without re-centering
    Connector 20-pin marine
    Velocity output 40 V peak-to-peak differential
    Selectable XYZ or UVW mode
    Mass position output Three independent voltage outputs
    Calibration input Single voltage input for all channels, indepdendent calibration enabled for each channel
    Calibration in XYZ or UVW
    Control lines Auto-level and Mass Center, Calibration Enable, XYZ/UVW mode
    Serial port RS-232 compatible serial IP (SLIP)
    Onboard web server standard HTTP
    For enhanced instrument control and status: self-levelling and mass centering, UVW/XYZ mode, short/long-period mode, firmware updates, temperature, mass position, instrument status, serial number and factory info
    Supply voltage 9 to 36 Volts DC isolated input
    Power consumption 560 mW typical at 15 V input
    Protection Reverse-voltage protection
    Auto-resettable over-current protection (no fuse to replace)
    Case design Stainless steel pressure vessel, submersible
    Diameter 143 mm (5.63")
    Height 432 mm (17") not including connector or feet
    Weight 16 kg
    Handling Eye bolt on lid for lifting cable
    1300 lbf (5800N) rated
    Operating temperature -20°C to +60°C (ultra-low temperature option available, please contact Nanometrics)
    Storage temperature -40°C to +70°C
    Water immersion Rated to IP68 and NEMA6P for prolonged submersion
    Shock 20 g half sine, 5 ms without damage, 6 axis
    No mass lock required for transport
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