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TRANSMED
Presentation > System Description

Description of the TRANSMED system

1. Main characteristics

  • ON/OFF of the pump autonomous in function of the ships speed (no pumping of dirty waters in harbours=> data quality)
  • High precision and frequency measurements of the temperature with a SBE38 as close as possible to the water inlet (SST data quality)
  • START/STOP of data acquisition in function of the speed (no human intervention requested)
  • Auto reboot after PWR failure (no human intervention requested)
  • No requirement for freshwater, anti-fouling rings included (no human intervention requested, lower maintenance frequency)
  • No through-hull valves (low installation cost)
  • Thermosalinometer SBE45 (lower cost, simpler installation, requests smaller room, no freshwater)
  • Automated full resolution data transmission in near real time, depending on the ships and company communication facility (operational oceanography and research)
  • Basic system (with adaptations to each ship), interchangeable, all identical, 1 configuration standard file (network)
  • Softs in open source (network)

2. Schematics


diagram

marfret description
Legend: the schematic operation diagram of the TRANSMED system (top), and the detailed seawater circuit as installed on the M/V "Marfret Niolon" (bottom).

3. The instruments

(as of 2014) Thermosalinometer SeaBird SBE45 (http://www.seabird.com/sbe45-thermosalinograph ) Thermometer SeaBird SBE38 ( http://www.seabird.com/sbe38-thermometer )

4. Data flow

(see also data )

dataflow

5. Data quality

The thermosalinometer SBE 45 probes are first post-calibrated ("as is" ) by the manufacturer SeaBird on a ~yearly basis, and then the conductivity cells are systematically cleaned and replatinized, which ensures that the salinity data are not questionable over the time series, yielding at least yearly reference points for climatological issues. Salinity samples are also drawn from time to time. Each thermometer SBE 38 probe has been recalibrated by the manufacturer SeaBird following 1 or 2 years of service, in order to check their stability in the TRANSMED system and environment. Since the drift is <0.0001°C/year, the recalibrations will be scheduled every 3-5 years, which is sufficient to ensure SST reference points for climatological issues.

recal
Legend: the non-significant drifts in both temperature and salinity computed from the recalibrations following ~22 months of service (link to corresponding data set plot ) validate the engineering design of the TRANSMED system, and confirm that an autonomous system can be run and yield high-quality data.