idronaut Ocean Seven 310 - Conductivity Compensated at 20 °C

SECTION ONE – SYSTEM DESCRIPTION
IDRONAUT – Brugherio (MB) OCEAN SEVEN 310 CTD 01-2019
15
counts per pH unit = Delta counts per pH unit (value factory set)
pH temperature compensation = 54.2 + (Temperature x 0.1984)
Temperature = sample temperature
54.2 = Nerst constant at 0° C
0.1984 = mV per pH unit per Centigrade degree
The above calculation is based on the following assumption:
The NERST equation, E = E0 + 2.303 RT/nF log a, predicts the theoretical output of any electrochemical cell.
Applying this equation to the glass electrode system, it can be shown that the mV response per pH unit varies with
centigrade temperature in the following way:
0°C 54.20 mV/pH 37°C 61.53 mV/pH
25°C 59.16 mV/pH 50°C 64.12 mV/pH
30°C 60.15 mV/pH 100°C 74.04 mV/pH
The potential response of the electrode system changes 0.1984 mV per pH unit per Centigrade degree.
1.16.3 Conductivity compensated at 20 °C
As reported in the Ambühl formula, the conductivity is compensated with the following calculation:
K = a - b x temp + c x temp2 - d x temp3
cond 20°C = cond x K
Where:
cond = conductivity sensor output a = 1.721183 c = 0.0011484224
temp = temperature sensor output b = 0.05413696 d = 0.00001226563
STANDARD SEA WATER K15 0,99999 - VERSUS TEMPERATURE TABLE
TEMP COND TEMP COND TEMP COND
°C mS/cm °C mS/cm °C mS/cm
10.00 38.08 16.75 44.64 23.50 51.49
10.25 38.32 17.00 44.89 23.75 51.75
10.50 38.56 17.25 45.14 24.00 52.01
10.75 38.79 17.50 45.39 24.25 52.27
11.00 39.03 17.75 45.64 24.50 52.53
11.25 39.27 18.00 45.89 24.75 52.79
11.50 39.51 18.25 46.14 25.00 53.05
11.75 39.75 18.50 46.39 25.25 53.32
12.00 39.99 18.75 46.64 25.50 53.58
12.25 40.23 19.00 46.89 25.75 53.84
12.50 40.47 19.25 47.14 26.00 54.10
12.75 40.71 19.50 47.40 26.25 54.36
13.00 40.95 19.75 47.65 26.50 54.63
13.25 41.20 20.00 47.90 26.75 54.89
13.50 41.44 20.25 48.16 27.00 55.15
13.75 41.68 20.50 48.41 27.25 55.42
14.00 41.93 20.75 48.67 27.50 55.68
14.25 42.17 21.00 48.92 27.75 55.94
14.50 42.42 21.25 49.18 28.00 56.21
14.75 42.66 21.50 49.43 28.25 56.47
15.00 42.91 21.75 49.69 28.50 56.74
15.25 43.15 22.00 49.95 28.75 57.01
15.50 43.40 22.25 50.20 29.00 57.27
15.75 43.65 22.50 50.46 29.25 57.54
16.00 43.89 22.75 50.72 29.50 57.80
16.25 44.14 23.00 50.98 29.75 58.07
16.50 44.39 23.25 51.24 30.00 58.34