Consider an RBRconcerto C.T.D.DO logger, where the DO channel is a RBRoptode. The RBRoptode transfers both the foil temperature and the dissolved oxygen concentration (not compensated for salinity). The RBRconcerto 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
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 atm. 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 RBRoptode. Please note that those coefficients are used and stored only by the logger, not the RBRoptode.
Example commands:
<< calibration 4 type = doxy23
( Confirm the channel type )
>> calibration 4
<< calibration 4 type = doxy23, datetime = 20160401120005, c0 = 0,c1 = 1, c2 = 3.25e-5, n0 = 5, n1 = 8, n2 = 3, n3 = value
( Request confirmation of everything )