Salted or fresh water

[Anton Lundin]

On 30 June, 2015 - Stan wrote:

> Hi,
> 
> Does anybody know how to configure lidivecomputer in order to get depth in
> fresh water. (Assuming it calibrated for salted water).
> For the Reefnet Sensus Ultra, I get the raw pressure and then I compute the
> depth.
> 
> I guess there is something to change in units.h ?
> 

Looking at the code, you can adjust the calibration values you're self
by calling:

reefnet_sensusultra_parser_set_calibration(dc_parser_t *abstract, double atmospheric, double hydrostatic)


The defaults are:
#define ATM         101325.0
#define GRAVITY     9.80665

parser->atmospheric = ATM;
parser->hydrostatic = 1025.0 * GRAVITY;


And the depth returned is computed by:

#define BAR         100000.0

sample.depth = (depth * BAR / 1000.0 - parser->atmospheric) / parser->hydrostatic;


So, in my tired mind, something like:
reefnet_sensusultra_parser_set_calibration(parser, ATM, 1000.0 * GRAVITY);


Should give you your depth for fresh water.


//Anton


-- 
Anton Lundin	+46702-161604