Conductivity - corrected for temperature and pressure

Let us consider a conductivity sensor integrated on the RBRconcerto³ C.T.D. The conductivity reading from Channel-1 without corrections is given by a simple linear function:

$//<![CDATA[ \begin{array}{l}Craw = c_0 + c_1 \cdot R\end{array} //]]>$

where R is the normalized voltage ratio from Channel-1 monitoring conductivity,  c0,c1  are the core coefficients of the linear equation, and Craw is the uncorrected conductivity output, reported in mS/cm for RBR marine instruments.

The equation which corrects the output for the effects of both temperature and pressure on the conductivity cell is:

$//<![CDATA[ \begin{array}{l}Corr = \dfrac{Craw - Kc_1 \cdot (T - Tcal)}{1 + Kc_2 \cdot (T - Tcal) + Kc_3 \cdot (Pcorr - Pcal)}\end{array} //]]>$

Casting the equation into the style used by the logger would give:
$//<![CDATA[ \begin{array}{l}Corr = \dfrac{Craw - x_0 \cdot (value(n_0) - x_3)}{1 + x_1 \cdot (value(n_0) - x_3) + x_2 \cdot (value(n_1) - x_4)}\end{array} //]]>$

where

• Craw is the uncorrected conductivity,  c0    +    c1  ×  R
• x0 ,  x1 ,  x2 correspond directly to the constants "Kc1", "Kc2" and "Kc3"
• x3   is the calibration temperature "Tcal" in °C
• x4 is the calibration pressure "Pcal" in dbar
• n0   is the index of the temperature channel, in this example 2
• value( n0 ) is the final output value of the temperature channel in °C
• n1    is the index of the pressure channel, in this example 3
  value( n1 ) is the final output value of the pressure channel in dbar
• Ccorr is the corrected output in mS/cm