KAIYO KY09-07 Conductivity-Temperature-Depth Profiler (CTD) Calibration Information

  1. Sensors
  2. • Water Temperature (Type : SBE3, S/N : 032730)
    (a) Calibration date
    Pre-calibration : 16 Jun.,2009 at SBE T-sensor
    Post-calibration: 11 Feb.,2010 at SBE T-sensor
    (b) Drift
    -0.00039 degrees-C/year
    (c) Estimated error
    As presented above, the drift rate for temperature is calculated from pre and post calibrations as -0.00039 degrees-C/year. Hypothesizing the linearity in T-sensor drift, the error of water temperature is tried to estimate using the drift rate.
    From pre-calibration date, 16 Jun.,2009 until the last day of KY09-07 on 07 Sep.,2009, it takes about 0.23 year. Then the error of water temperature data observed by CTD is estimated as -0.0001 degrees-C for the cruise of KY09-07.

    • Salinity (Type : SBE4, S/N : 042240)
    (a) Calibration date
    Pre-calibration : 19 Jun.,2009 at SBE C-sensor
    Post-calibration: 04 Feb.,2010 at SBE C-sensor
    (b) Drift
    -0.00010 PSU/month

    • Pressure (Type : SBE9plus, S/N : 94766)
    Calibration date, coefficients
    The calibration coefficients for the sensor are as follows;
    Pre-calibration : 16 Jul.,2009 at SBE slope1: 0.99992 , offset1: -0.5951
    Post-calibration: 17 Nov.,2009 at SBE slope2: 0.99991 , offset2: -0.5099
    The observed value is computed as
    Observed value [dbar] = slope1 * computed pressure[dbar] + offset1[dbar]

  3. Comparison with sampled water analysis
  4. As for the cruise of KY09-07, there is no data for comparison.