Metadata Report for BODC Series Reference Number 41214
No Problem Report Found in the Database
Open Data supplied by Natural Environment Research Council (NERC)
You must always use the following attribution statement to acknowledge the source of the information: "Contains data supplied by Natural Environment Research Council."
IOS Off-Shore Pressure Recorder Mark III
The main part of the capsule is a forged aluminium sphere of 0.66m internal diameter, which contains the data logging system, acoustic command and release units and all battery supplies. Each half of the sphere is bolted to a central equatorial ring, a seal being provided by O rings.
There are twelve outlets through this ring for Marsh Marine type electrical connectors. The sphere is housed in a free flooding tubular aluminium alloy frame. Also mounted on this frame are 2 pressure transducers, a sea temperature unit, 2 subsidary platinum resistance thermometers for measuring sea temperature and 2 wound nickel scrolls that act as acoustic pinger beacons. The frame and sphere, complete with attachments, have a positive buoyancy, and in order to anchor them, they are mounted on a steel tripod. The tripod is attached to the main frame by a central pyro-release unit.
The system incorporates a commercial data logger modified to operate in the deep sea capsule. The logger will accept input from a total of twelve separate sources or channels. The temperature and pressure sensors have variable frequency outputs. The frequencies are counted over a 890 second period and the total count for each channel is then recorded during a scan of all channels which lasts for 10 seconds. Thus the averaged integrated pressure and temperature values are logged every 15 minutes. Temperature is measured to correct for the temperature coefficient of the pressure transducers.
Data Processing Notes
Clock lost 20 seconds over 22 days 18 hours 0 minutes 20 seconds; the cycle interval and time values have been corrected.
|OSTG Mark III||Number 17|
|Sensors||SG 1D/10 (BODC Series Ref. 41226) |
SG 1D/8 (BODC Series Ref. 41214)
|Nominal sampling interval||900 seconds|
|Integration period||890 seconds|
IOS Data Processing of Off-Shore Pressure Recorder Data
Data processing comprises 2 stages:-
Instrumental drift and depth are removed, thus the drift free series is produced with an artificial mean of zero.
Generally the pressure values have been obtained by integration and averaging over the sampling interval, followed by logging; hence the time value assigned to a data cycle has been chosen as the mid-point between the start and end time of each interval. Some pressure records have been sample rate reduced from the basic time step of the recorder to produce either hourly or 15 minute values, incorporating any timing corrections due to clock error.
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|