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Metadata Report for BODC Series Reference Number 925482

Metadata Summary

Data Description

Data Category CTD or STD cast
Instrument Type
Falmouth Scientific Instruments NXIC CTD Series  CTD; water temperature sensor; salinity sensor
Instrument Mounting research vessel
Originating Country United Kingdom
Originator Ms Sarah Hughes
Originating Organization Fisheries Research Services Aberdeen Marine Laboratory (now Marine Scotland Aberdeen Marine Laboratory)
Processing Status banked
Online delivery of data Download available - Ocean Data View (ODV) format
Project(s) -

Data Identifiers

Originator's Identifier NM11/08/146
BODC Series Reference 925482

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 2008-10-10 09:19
End Time (yyyy-mm-dd hh:mm) -
Nominal Cycle Interval 1.0 decibars

Spatial Co-ordinates

Latitude 56.16083 N ( 56° 9.6' N )
Longitude 5.78700 W ( 5° 47.2' W )
Positional Uncertainty 0.05 to 0.1 n.miles
Minimum Sensor or Sampling Depth 0.99 m
Maximum Sensor or Sampling Depth 115.9 m
Minimum Sensor or Sampling Height 29.1 m
Maximum Sensor or Sampling Height 144.01 m
Sea Floor Depth 145.0 m
Sea Floor Depth Source -
Sensor or Sampling Distribution Variable common depth - All sensors are grouped effectively at the same depth, but this depth varies significantly during the series
Sensor or Sampling Depth Datum Instantaneous - Depth measured below water line or instantaneous water body surface
Sea Floor Depth Datum Instantaneous - Depth measured below water line or instantaneous water body surface


BODC CODERankUnitsTitle
ACYCAA011DimensionlessSequence number
CNDCST011Siemens per metreElectrical conductivity of the water body by CTD
PRESPR011DecibarsPressure (spatial coordinate) exerted by the water body by profiling pressure sensor and correction to read zero at sea level
PSALST011DimensionlessPractical salinity of the water body by CTD and computation using UNESCO 1983 algorithm
TEMPST011Degrees CelsiusTemperature of the water body by CTD or STD

Definition of Rank

  • Rank 1 is a one-dimensional parameter
  • Rank 2 is a two-dimensional parameter
  • Rank 0 is a one-dimensional parameter describing the second dimension of a two-dimensional parameter (e.g. bin depths for moored ADCP data)

Problem Reports

No Problem Report Found in the Database

Data Access Policy

Public domain data

These data have no specific confidentiality restrictions for users. However, users must acknowledge data sources as it is not ethical to publish data without proper attribution. Any publication or other output resulting from usage of the data should include an acknowledgment.

The recommended acknowledgment is

"This study uses data from the data source/organisation/programme, provided by the British Oceanographic Data Centre and funded by the funding body."

Narrative Documents

Falmouth Scientific NXIC CTD Series

The FSI NXIC CTD Series is a collection of rugged Conductivity-Temperature-Depth profilers that utilise the patented Non-eXternal Inductive Cell (NXIC) conductivity sensor, which was originally developed for the US Navy DT-705 Sound Velocity/Salinity sensor. The CTDs are fast sampling, fully integrated instruments with optional battery power, datalogging and external analog sensor input.

Models in the collection include the NXIC CT Bio Direct Read-500M, NXIC CTD Bio Direct Read-500M, NXIC CTD Bio Auto-500M, NXIC CTD Direct Read-500M, NXIC CTD Direct Read-700M, NXIC CTD Auto-500M, NXIC CTD Auto-700M, NXIC CTD-ADC with external sensors, and the NXIC ETSG Thermosalinograph. Parameters are measured to an accuracy ranging from 0.002-0.010 mS/cm for conductivity, 0.005 degC for temperature and 0.08% for full scale pressure. Now marketed by Teledyne RD Instruments.


  Conductivity Temperature Pressure
Sensor type Inductive cell Thermistor Precision-machined Silicon
Range 0 to 9.0 S m-1 -5 to 45°C user specified
Accuracy ± 0.0002 S m-1 ± 0.005°C 0.08 % full scale
Stability ± 0.00005 S cm-1 month-1 0.0005°C month-1 ± 0.004 %
Resolution 0.00001 S m-1 0.001°C 0.001 % full scale
Response 5.0 cm at 1 m sec-1 flow 100 msec 25 msec

Further details can be found in the manufacturer's specification sheet and Series Brochure.

Instrument Description

CTD Unit and Auxiliary Sensors

A Falmouth Scientific Inc. NXIC CTD unit was used. The CTD unit included the following sensors.

Sensor Manufacturer Model Serial number Calibration date
Pressure Falmouth Scientific Inc. NXIC 2061 28/12/2006
Temperature Falmouth Scientific Inc. NXIC 2061 28/12/2006
Conductivity Falmouth Scientific Inc. NXIC 2061 28/12/2006

BODC Processing

Data were received by BODC in one ASCII format file that was subsequently split into 15 separate files, one for each CTD profile. The series were reformatted to the internal QXF format using BODC transfer function 340. The following table details mapping of variables to BODC parameter codes.

Original parameter name Original Units Description BODC Parameter Code BODC Units Comments
Pressure Decibars Pressure exerted by the water column PRESPR01 Decibars  
Temperature °C Temperature of the water column TEMPST01 °C  
Conductivity mS cm-1 Electrical conductivity of the water column CNDCST01 S m-1 Conversion by transfer (mS cm-1 x 0.1)
Salinity   Salinity of the water column PSALST01 Dimensionless Derived by transfer using UNESCO 1983 algorithm

Following transfer to QXF, the data were screened using BODC's in-house visualisation software, EDSERPLO. Any data considered as suspect were flagged 'M'. Flags from the originator marking suspect data were retained during transfer and flagged 'L'.

Originator's Data Processing

Sampling Strategy

A total of 15 CTD casts were performed on FRV Alba na Mara cruise 1108A part 1 (06 October 2008 - 11 October 2008) in the Firth of Lorn, west Scotland. The CTDs were carried out close to the coast in all cases. The data were collected between 06:00 hours on 09 October and 15:00 hours on 10 October 2008.

Data Processing

The raw CTD data files were processed through the Falmouth Scientific NXIC CTDPro data processing software following standard procedures. The originators used in-house interactive visual display editing software to edit out individual spikes in the primary temperature and conductivity channels. An ASCII file was generated for each CTD cast and all files from a cruise were concatenated into one ASCII file which was submitted to BODC.

Project Information

No Project Information held for the Series

Data Activity or Cruise Information


Cruise Name 1108A Part 1
Departure Date 2008-10-06
Arrival Date 2008-10-11
Principal Scientist(s)Bill Turrell (Fisheries Research Services Aberdeen Marine Laboratory)
Ship FRV Alba Na Mara

Complete Cruise Metadata Report is available here

Fixed Station Information

No Fixed Station Information held for the Series

BODC Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:

Flag Description
Blank Unqualified
< 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.)
D Thermometric depth
E End of CTD Down/Up Cast
G Non-taxonomic biological characteristic uncertainty
H Extrapolated value
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
N Null value
O Improbable value - user quality control
P Trace/calm
Q Indeterminate
R Replacement value
S Estimated value
T Interpolated value
U Uncalibrated
W Control value
X Excessive difference

SeaDataNet Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:

Flag Description
0 no quality control
1 good value
2 probably good value
3 probably bad value
4 bad value
5 changed value
6 value below detection
7 value in excess
8 interpolated value
9 missing value
A value phenomenon uncertain
B nominal value
Q value below limit of quantification