# Example 17: corr_o2conc_garcia, O2 concentration compensated for salinity and pressure

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:

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

where T is the water temperature (in °C), and

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.

## Examples

CODE
>> calibration 4 type
<< calibration 4 type = doxy23

Confirm the channel type.

CODE
>> calibration 4
<< calibration 4 type = doxy23, datetime = 20171201000000, c0 = 0,c1 = 1, c2 = 3.25e-5, n0 = 5, n1 = 8, n2 = 3, n3 = value 

Request confirmation of all calibration coefficients.

JavaScript errors detected