Trillium Posthole Broadband Seismometer

Summary

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.

TECHNOLOGY
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
PERFORMANCE
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
INTERFACE
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
POWER
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)
PHYSICAL
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
ENVIRONMENTAL
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

Performance