Metadata Report for BODC Series Reference Number 36758
No Problem Report Found in the Database
Open Data supplied by Natural Environment Research Council (NERC)
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IOS Mk IV Pressure Recorder
This instrument was developed at I.O.S. Bidston and is a deep water pressure recorder (i.e. used at depths between 300m and 5000m). Each recorder consists of one or two Bell and Howell strain gauges and/or a Digiquartz pressure sensor and a temperature sensor.
The sensors are interfaced into a Seadata cassette recording system. Sampling is usually every 3.75 minutes with the integration period equal to the sampling interval, but may be set to other sampling intervals. For example with a 3 second sampling interval and integration period the instrument may be used as a wave recorder.
The recorder is housed in a tubular aluminium frame 1.3m in diameter by 1.4m in height attached to a disposable steel ballast weight. The data logger together with the associated battery supply is lowered into a central 15cm (internal diameter) aluminium tube. Sensors are mounted externally with Marsh Marine connectors. The assembly free falls to the sea floor. An acoustic release system is used to separate the ballast weight and buoyancy is provided by Corning glass spheres attached to the aluminium frame.
Data Processing Notes
Clock lost 240 seconds over 127 days 3 hours 7.5 minutes; the original cycle interval and time values have been corrected.
|OSTG Mark IV Sensors||SG1/D12 (BODC Series Ref. 36734) |
DQ662 (BODC Series Ref. 36746)
DQ2622 (BODC Series Ref. 36758)
|Nominal sampling interval||225secs|
|Actual sampling interval||225.001390secs|
IOS Data Processing of Off-Shore Pressure Recorder Data
Data processing consists of two stages:-
Pressures have been sample rate reduced from the basic time step of the recorder to produce the hourly values and have been interpolated by a cubic spline to generate the value on cardinal hours.
Instrumental drift has been removed and the drift free series is produced with an artificial mean value, usually of 100mbar.
No Project Information held for the Series
No Data Activity or Cruise Information held for the Series
No Fixed Station Information held for the Series
The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:
|<||Below detection limit|
|>||In excess of quoted value|
|A||Taxonomic flag for affinis (aff.)|
|B||Beginning of CTD Down/Up Cast|
|C||Taxonomic flag for confer (cf.)|
|E||End of CTD Down/Up Cast|
|G||Non-taxonomic biological characteristic uncertainty|
|I||Taxonomic flag for single species (sp.)|
|K||Improbable value - unknown quality control source|
|L||Improbable value - originator's quality control|
|M||Improbable value - BODC quality control|
|O||Improbable value - user quality control|
|0||no quality control|
|2||probably good value|
|3||probably bad value|
|6||value below detection|
|7||value in excess|
|A||value phenomenon uncertain|
|Q||value below limit of quantification|