diff options
Diffstat (limited to 'core/gas.c')
| -rw-r--r-- | core/gas.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/core/gas.c b/core/gas.c index e62bed1ea..8dbfe61cb 100644 --- a/core/gas.c +++ b/core/gas.c @@ -96,6 +96,15 @@ fraction_t get_gas_component_fraction(struct gasmix mix, enum gas_component comp } } +// O2 pressure in mbar according to the steady state model for the PSCR +// NB: Ambient pressure comes in bar! +int pscr_o2(const double amb_pressure, struct gasmix mix) { + int o2 = get_o2(mix) * amb_pressure - (int)((1.0 - get_o2(mix) / 1000.0) * prefs.o2consumption / (prefs.bottomsac * prefs.pscr_ratio) * 1000000); + if (o2 < 0.0) // He's dead, Jim. + o2 = 0.0; + return o2; +} + /* fill_pressures(): Compute partial gas pressures in bar from gasmix and ambient pressures, possibly for OC or CCR, to be * extended to PSCT. This function does the calculations of gas pressures applicable to a single point on the dive profile. * The structure "pressures" is used to return calculated gas pressures to the calling software. @@ -123,9 +132,7 @@ void fill_pressures(struct gas_pressures *pressures, const double amb_pressure, } } 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 / (prefs.bottomsac * prefs.pscr_ratio / 1000.0); - if (pressures->o2 < 0) // He's dead, Jim. - pressures->o2 = 0; + pressures->o2 = pscr_o2(amb_pressure, mix) / 1000.0; if (get_o2(mix) != 1000) { pressures->he = (amb_pressure - pressures->o2) * get_he(mix) / (1000.0 - get_o2(mix)); pressures->n2 = (amb_pressure - pressures->o2) * get_n2(mix) / (1000.0 - get_o2(mix)); |