diff options
Diffstat (limited to 'core')
| -rw-r--r-- | core/divelist.c | 26 | ||||
| -rw-r--r-- | core/gas.c | 13 | ||||
| -rw-r--r-- | core/gas.h | 2 |
3 files changed, 32 insertions, 9 deletions
diff --git a/core/divelist.c b/core/divelist.c index a6debfb20..379e33eea 100644 --- a/core/divelist.c +++ b/core/divelist.c @@ -114,9 +114,16 @@ static int calculate_otu(const struct dive *dive) po2f = MIN((int) sample->setpoint.mbar, depth_to_mbar(sample->depth.mm, dive)); } else { // For OC and rebreather without o2 sensor/setpoint - int o2 = active_o2(dive, dc, psample->time); // ... calculate po2 from depth and FiO2. - po2i = lrint(o2 * depth_to_bar(psample->depth.mm, dive)); // (initial) po2 at start of segment - po2f = lrint(o2 * depth_to_bar(sample->depth.mm, dive)); // (final) po2 at end of segment + double amb_presure = depth_to_bar(sample->depth.mm, dive); + double pamb_pressure = depth_to_bar(psample->depth.mm , dive); + if (dc->divemode == PSCR) { + po2i = pscr_o2(pamb_pressure, get_gasmix_at_time(dive, dc, psample->time)); + po2f = pscr_o2(amb_presure, get_gasmix_at_time(dive, dc, sample->time)); + } else { + int o2 = active_o2(dive, dc, psample->time); // ... calculate po2 from depth and FiO2. + po2i = lrint(o2 * pamb_pressure); // (initial) po2 at start of segment + po2f = lrint(o2 * amb_presure); // (final) po2 at end of segment + } } } if ((po2i > 500) || (po2f > 500)) { // If PO2 in segment is above 500 mbar then calculate otu @@ -173,9 +180,16 @@ static double calculate_cns_dive(const struct dive *dive) trueo2 = true; } if (!trueo2) { - int o2 = active_o2(dive, dc, psample->time); // For OC and rebreather without o2 sensor: - po2i = lrint(o2 * depth_to_bar(psample->depth.mm, dive)); // (initial) po2 at start of segment - po2f = lrint(o2 * depth_to_bar(sample->depth.mm, dive)); // (final) po2 at end of segment + double amb_presure = depth_to_bar(sample->depth.mm, dive); + double pamb_pressure = depth_to_bar(psample->depth.mm , dive); + if (dc->divemode == PSCR) { + po2i = pscr_o2(pamb_pressure, get_gasmix_at_time(dive, dc, psample->time)); + po2f = pscr_o2(amb_presure, get_gasmix_at_time(dive, dc, sample->time)); + } else { + int o2 = active_o2(dive, dc, psample->time); // ... calculate po2 from depth and FiO2. + po2i = lrint(o2 * pamb_pressure); // (initial) po2 at start of segment + po2f = lrint(o2 * amb_presure); // (final) po2 at end of segment + } } int po2avg = (po2i + po2f) / 2; // po2i now holds the mean po2 of initial and final po2 values of segment. /* Don't increase CNS when po2 below 500 matm */ 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)); diff --git a/core/gas.h b/core/gas.h index cd7c9e389..83eef72e9 100644 --- a/core/gas.h +++ b/core/gas.h @@ -59,6 +59,8 @@ static inline int get_n2(struct gasmix mix) return 1000 - get_o2(mix) - get_he(mix); } +int pscr_o2(const double amb_pressure, struct gasmix mix); + struct gas_pressures { double o2, n2, he; }; |