diff --git a/RaspberryPi/calculate.c b/RaspberryPi/calculate.c
index 2422868..75ad7c3 100644
--- a/RaspberryPi/calculate.c
+++ b/RaspberryPi/calculate.c
@@ -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) {
-    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) {
+  if (temperature >= 0) {
     a = 7.6;
     b = 240.7;
   }
-  
-  
-  float sdd_T = sdd(sensor->temperature);
-  float dd = dd(sensor->humidity, sensor->temperature);
-  float relativeHumidity = r( 
+  return b * v(relativeHumidity, temperature) / (a - v(relativeHumidity, temperature));
+}
 
+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;
 }