corr_pres2 - pressure with temperature correction

For an analogically interfaced pressure transducer, the pressure reading without correction for the effect of temperature on the sensor, is given by a cubic polynomial:

where R is the normalized voltage ratio read by the ADC monitoring pressure, c0...c3 are the core coefficients of the cubic polynomial equation, and Praw is the uncorrected pressure output, reported in dbar for RBR instruments.

The equation which accounts for residual temperature sensitivity of the pressure sensor is:

Casting this into the form used by the logger would yield:

where

• Praw is the cubic polynomial in R, as before.

• x0 is the calibration pressure 'Pcal' in dbar.

• x1, x2, x3, x4  correspond directly to the constants "Kp1" through "Kp4".

• x5 is the calibration temperature "Tcal" in °C.

• n0 is the label of the temperature channel near the transducer "T", in the examples pressuretemperature_00
  value(n0) is the final output value of the temperature channel in °C.

• Pcorr is the corrected output in dbar.

Examples

>> calibration pressure_00 datetime=20251001000000 c0=0.2346 c1=120.9873 c2=2. 7356 c3=0.7

Set the core coefficients.

>> calibration pressure_00 datetime=20251001000000 x0=9.983 x1=0.2003 x2=0.2943 x3=0.0721 x4=0.1049 x5=21.29

Set the cross-channel correction coefficients.

>> calibration pressure_00
<< calibration pressure_00 datetime=20251001000000 equation=corr_pres2 offset=0.0000000e+000 slope=1.0000000e+000 c0=0.2346 c1=120.9873 c2=2 7356 c3=0.7 x0=9.983 x1=0.2003 x2=0.2943 x3=0.0721 x4=0.1049 x5=21.29 n0=pressuretemeprature_00

Request confirmation of all calibration coefficients.