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Finished calculation

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Structix
2017-08-24 12:30:30 +00:00
parent bac990f73f
commit 50c5686732
1 changed files with 25 additions and 26 deletions
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45
RaspberryPi/calculate.c
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@@ -3,6 +3,8 @@
#include <math.h> /* link against math lib */
#include "calculate.h"
#define R 8314.3 //J/(kmol*K) (universelle Gaskonstante)
#define mw 18.016 //kg/kmol (Molekulargewicht des Wasserdampfes)
/*
Bezeichnungen:
@@ -31,53 +33,50 @@ Formeln:
AF(r,TK) = 10^5 * mw/R* * DD(r,T)/TK; AF(TD,TK) = 10^5 * mw/R* * SDD(TD)/TK
*/
float sdd(float temperature) {
static float sdd(float temperature) {
//select constant based on input temperature
float a = 7.5, b = 237.3;
if (sensor->temperature >= 0) {
if (temperature >= 0) {
a = 7.6;
b = 240.7;
}
return 6.1078 * pow(10, (a*temperature) / (b*temperature));
return 6.1078 * pow(10, (a * temperature) / (b + temperature));
}
float dd(float relativeHumidity, float temperature) {
static float dd(float relativeHumidity, float temperature) {
return relativeHumidity / 100 * sdd(temperature);
}
float r(float temperature, float dewTemperature) {
static float r(float temperature, float dewTemperature) {
/* This is optional. Necessary with dew point measurements. */
return 100 * sdd(dewTemperature) / sdd(temperature);
}
//TD(r,T) = b*v/(a-v) mit v(r,T) = log10(DD(r,T)/6.1078)
float v(float relativeHumidity, float temperature) {
static float v(float relativeHumidity, float temperature) {
log10(dd(relativeHumidity, temperature)/6.1078);
}
float td(float relativeHumidity, float temperature) {
static float td(float relativeHumidity, float temperature) {
//select constant based on input temperature
float a = 7.5, b = 237.3;
if (sensor->temperature >= 0) {
if (temperature >= 0) {
a = 7.6;
b = 240.7;
}
return b * v(relativeHumidity, temperature) / (a - v(relativeHumidity, temperature));
}
float absoluteHumidity(sensor *sensor) {
//select constant based on input temperature
float a = 7.5, b = 237.3;
if (sensor->temperature >= 0) {
a = 7.6;
b = 240.7;
}
float sdd_T = sdd(sensor->temperature);
float dd = dd(sensor->humidity, sensor->temperature);
float relativeHumidity = r(
static float af(float relativeHumidity, float temperature) {
float tk = temperature + 273.15;
return pow(10, 5) * mw/R * dd(relativeHumidity, temperature) / tk;
}
float absoluteHumidity(sensor *sensor) {
return af(sensor->humidity, sensor->temperature);
}
int compareSensors(sensor *inside, sensor *outside) {
if (absoluteHumidity(inside) <= absoluteHumidity(outside)) return 1;
return 0;
}