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:
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:
Casting the equation into the style used by the logger would give:
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 dbarCcorr is the corrected output in mS/cm