Metadata Report for BODC Series Reference Number 37006
No Problem Report Found in the Database
Open Data supplied by Natural Environment Research Council (NERC)
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Aanderaa Pressure Recorder Type TG-4A
The Aanderaa recorder uses a Digiquartz type 2-300a quartz crystal pressure transducer. The pressure sensor consists of a convoluted bellows linked to a 40kHz quartz crystal resonator coupled by piezoelectric action to an electronic resonator. Data are recorded on to 0.25 inch magnetic tape on an Aanderaa data logger in the same case. A quartz crystal clock is used for controlling the sampling interval.
The data are recorded as 10 bit binary words in serial form with the frequency count from the sensor stored as the most and least significant counts. The pressure recorder is a deep water instrument and is usually deployed on a pop up mooring.
Data Processing Notes
Instrument samples pressure and temperature alternately, therefore interval between 2 consecutive pressure values is 30 minutes. Clock gained 27 seconds over 94 days 15 hours 0 minutes 3 seconds; the original cycle interval and time values have been corrected.
|Aanderaa 4A||(BODC Series Ref. 37006)|
|Nominal sampling interval||1800 secs|
|Integration period||30 secs|
|Actual sampling interval||29.999901mins|
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|