Consider an RBRconcerto³ C.T.D.DO logger, where the DO channel is a RBRcoda ODO. The RBRcoda ODO transfers both the foil temperature and the dissolved oxygen concentration (not compensated for salinity). The RBRconcerto³ calculates the concentration compensated for salinity and pressure first:
$O2corr = (C_0 + C_1 \cdot O2unc) \cdot exp(S \cdot (Gb_0 + Gb_1 \cdot Ts + Gb_2 \cdot Ts^2 + Gb_3 \cdot Ts^3) + Gc_0 \cdot S^2) \cdot (1 + P \cdot C_2)$where
- O2corr is the corrected O2 concentration, compensated for salinity and pressure,
- O2unc is the uncompensated O2 concentration returned by the RBRoptode,
- C0 and C1 are corrections and scaling factors for the uncompensated O2 concentration,
- C2 is a correction factor for pressure,
- S is the salinity in PSU,
- P is sea pressure in dbar,
and
$Ts = ln(\dfrac{298.15 - T}{273.15 + T})$where T is the water temperature (in °C), and
\begin{equation*} \begin{aligned} Gb_0 & = -6.24097e-3 \\ Gb_1 & = -6.93498e-3 \\ Gb_2 & = -6.90358e-3 \\ Gb_3 & = -4.29155e-3 \\ Gc_0 & = -3.11680e-7 \end{aligned} \end{equation*}which correspond to Garcia and Gordon coefficients.
The corresponding logger coefficients are:
- c0 is C0
- c1 is C1
- c2 is C2
- n0 is the index of the water temperature channel
- n1 is the index of the salinity channel
- n2 is the index of the pressure channel
- n3 is the index of the atmospheric pressure channel (set to value in order to use settings atmosphere)
One might change c0 and c1 in order to perform a two point calibration to the RBRcoda ODO. Please note that those coefficients are used and stored only by the logger, not the RBRcoda ODO.
Confirm the channel type. Request confirmation of all calibration coefficients.Examples
<< calibration 4 type = doxy23
<< calibration 4 type = doxy23, datetime = 20171201000000, c0 = 0,c1 = 1, c2 = 3.25e-5, n0 = 5, n1 = 8, n2 = 3, n3 = value