SIO WideBand

SIO Long-Deployment Wideband OBS

Drawing of the SIO Wideband OBS. The data logger used for this instrument is identical to that used in the active source OBH/S. Longer duration is afforded by including a second cylinder for batteries. Additional release redundancy can be added through the use of a second acoustic unit with dual burn wires. An external sensor package contains a new Kinemetrics wideband, triaxial seismometer. The OBS/H is capable of more than 18 months of recording and a joint SIO/WHOI project will make a buried sensor available in the future.

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Technical Specifications: SIO Long-Deployment Wideband OBS

(Subject to Change)

Seismometer Kinemetrics Wide-band 3-component seismometer with flat velocity response from 30 mHz - 10 Hz. Gimbals will level seismometer if deployed within ±75° of vertical. Option to bury seismometer available in future.

Pressure Sensor HiTech HYI-90-U hydrophone with internal preamp. Bandwidth (-3 dB) is 50 mHz - 15 kHz. Differential Pressure Gauge (DPG) also available with response from 10 mHz - 10 Hz.

Digitizer L-CHEAPO 24-bit A/D. Dynamic range at 31.25 s/s is 130 dB and at 250 Hz is 124 dB. Uses the Cirrus/Crystal Semiconductor chip set CS5321-CS5322 - same as IRIS/PASSCAL

Sample Rates 500 Hz, 250 Hz, 125 Hz, 62.5 Hz, 31.25 Hz

Clock Seascan Precision Timebase. Drift rate is 1:3-5 x 10-8 (<0.5 ms/day before correction and <0.1 s/yr after correction)

Disk Capacity 9 GB hard disk

Data Offload SCSI transfer of data can be done through the end cap without opening the pressure case for experiments in which rapid deployments are necessary.

Battery Pack Batteries are mounted in the data logger pressure case and in battery case. Separate batteries power the acoustic release.

Recording duration Lithium battery pack can provide power at 31.25 s/s for 17.4 months (compressed) or at 62.5 s/s for 16.5 months (compressed).

Weight 450/350 lbs with/without anchor

Pressure Case 7" diameter Al cylinder

Release Double burnwire operated acoustically

Dimensions 51" high x 43" wide

Power 688 mW at 31.25 Hz (663 mW compressed) or 762 mW at 62.5 Hz (712 mW compressed)

Technical Specifications: SIO Long-Deployment Wideband OBS (Subject to Change)
Seismometer	Kinemetrics Wide-band 3-component seismometer with flat velocity response from 30 mHz - 10 Hz. Gimbals will level seismometer if deployed within ±75° of vertical. Option to bury seismometer available in future.
Pressure Sensor	HiTech HYI-90-U hydrophone with internal preamp. Bandwidth (-3 dB) is 50 mHz - 15 kHz. Differential Pressure Gauge (DPG) also available with response from 10 mHz - 10 Hz.
Digitizer	L-CHEAPO 24-bit A/D. Dynamic range at 31.25 s/s is 130 dB and at 250 Hz is 124 dB. Uses the Cirrus/Crystal Semiconductor chip set CS5321-CS5322 - same as IRIS/PASSCAL
Sample Rates	500 Hz, 250 Hz, 125 Hz, 62.5 Hz, 31.25 Hz
Clock	Seascan Precision Timebase. Drift rate is 1:3-5 x 10-8 (<0.5 ms/day before correction and <0.1 s/yr after correction)
Disk Capacity	9 GB hard disk
Data Offload	SCSI transfer of data can be done through the end cap without opening the pressure case for experiments in which rapid deployments are necessary.
Battery Pack	Batteries are mounted in the data logger pressure case and in battery case. Separate batteries power the acoustic release.
Recording duration	Lithium battery pack can provide power at 31.25 s/s for 17.4 months (compressed) or at 62.5 s/s for 16.5 months (compressed).
Weight	450/350 lbs with/without anchor
Pressure Case	7" diameter Al cylinder
Release	Double burnwire operated acoustically
Dimensions	51" high x 43" wide
Power	688 mW at 31.25 Hz (663 mW compressed) or 762 mW at 62.5 Hz (712 mW compressed)