diff options
| author |  Robert C. Helling <helling@atdotde.de> | 2015-01-19 11:32:27 +0100 |
|---|---|---|
| committer |  Dirk Hohndel <dirk@hohndel.org> | 2015-01-20 06:16:15 +1200 |
| commit | 837dcde0c180883e3d75e90459b06bde9789b797 (patch) | |
| tree | e215894a21c7bc305a2fa6bc4bfd85f018c75bff /dive.c | |
| parent | 86c961614bfa8ab9057319ea5f22816351a7f61a (diff) | |
| download | subsurface-837dcde0c180883e3d75e90459b06bde9789b797.tar.gz | |
Use SAC from preferences for PSCR oxygen drop
The ratio between SAC and oxygen metabolism rate can be assumed constant
but not the metabolism rate. So we better base our calculation on the ratio
that uses the SAC from the preferences as that pairs well with the O2
consumption from the preferences.
Hence we ran remove the sac parameter from fill_pressures().
Signed-off-by: Robert C. Helling <helling@atdotde.de>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Diffstat (limited to 'dive.c')
| -rw-r--r-- | dive.c | 17 |
1 files changed, 6 insertions, 11 deletions
@@ -1665,13 +1665,8 @@ int gasmix_distance(const struct gasmix *a, const struct gasmix *b) * *mix = structure containing cylinder gas mixture information. * This function called by: calculate_gas_information_new() in profile.c; add_segment() in deco.c. */ -extern void fill_pressures(struct gas_pressures *pressures, const double amb_pressure, const struct gasmix *mix, double po2, enum dive_comp_type divemode, int sac) +extern void fill_pressures(struct gas_pressures *pressures, const double amb_pressure, const struct gasmix *mix, double po2, enum dive_comp_type divemode) { - if (!sac) { - /* The SAC has not yet been computer, so use the default * - * We might try harder... */ - sac = prefs.bottomsac; - } if (po2) { // This is probably a CCR dive where pressures->o2 is defined if (po2 >= amb_pressure) { pressures->o2 = amb_pressure; @@ -1687,14 +1682,14 @@ extern void fill_pressures(struct gas_pressures *pressures, const double amb_pre } } else { if (divemode == PSCR) { /* The steady state approximation should be good enough */ - pressures->o2 = get_o2(mix) / 1000.0 * amb_pressure - (1.0 - get_o2(mix) / 1000.0) * prefs.o2consumption / (sac * prefs.pscr_ratio / 1000.0); + pressures->o2 = get_o2(mix) / 1000.0 * amb_pressure - (1.0 - get_o2(mix) / 1000.0) * prefs.o2consumption / (prefs.bottomsac * prefs.pscr_ratio / 1000.0); pressures->he = (amb_pressure - pressures->o2) * get_he(mix) / (1000.0 - get_o2(mix)); pressures->n2 = (amb_pressure - pressures->o2) * (1000 - get_o2(mix) - get_he(mix)) / (1000.0 - get_o2(mix)); } else { - // Open circuit dives: no gas pressure values available, they need to be calculated - pressures->o2 = get_o2(mix) / 1000.0 * amb_pressure; // These calculations are also used if the CCR calculation above.. - pressures->he = get_he(mix) / 1000.0 * amb_pressure; // ..returned a po2 of zero (i.e. o2 sensor data not resolvable) - pressures->n2 = (1000 - get_o2(mix) - get_he(mix)) / 1000.0 * amb_pressure; + // Open circuit dives: no gas pressure values available, they need to be calculated + pressures->o2 = get_o2(mix) / 1000.0 * amb_pressure; // These calculations are also used if the CCR calculation above.. + pressures->he = get_he(mix) / 1000.0 * amb_pressure; // ..returned a po2 of zero (i.e. o2 sensor data not resolvable) + pressures->n2 = (1000 - get_o2(mix) - get_he(mix)) / 1000.0 * amb_pressure; } } } |