From a Temp and Humidity sensor readings can anyone give me the mathematical formula for converting to" Temp and Humidity" to "Dew Point".
I would like to display
Temperature Humidity Dew Point
Tx
From a Temp and Humidity sensor readings can anyone give me the mathematical formula for converting to" Temp and Humidity" to "Dew Point".
I would like to display
Temperature Humidity Dew Point
Tx
Hello Farticus
Take a look here to acquire the knowledge:
From post #2 @paulpaulson , the Formula for Dew point is (Fig-1):
Figure-1:
Sketch:
char myData[20];
void setup()
{
Serial.begin(9600);
}
void loop()
{
Serial.println("Enter Temperature and Humidity as: TT.TT,HH.HH");
while (Serial.available() == 0)
{
;
}
byte m = Serial.readBytesUntil('\n', myData, sizeof(myData) - 1);
myData[m] = '\0';
//Serial.println(myData); //debugg
char *token;
token = strtok(myData, ",");
float ttF = atof(token);
//Serial.print(ttF, 2); Serial.print(' '); //debugg
//------------------------
token = strtok(NULL, ",");
float hhF = atof(token);
//Serial.println(hhF, 2); Serial.println(); //debugg
//----------------------
float dewPoint = calculateDewPoint(ttF, hhF);
Serial.print("Dew point: "); Serial.print(dewPoint, 2); Serial.println(" degC");
Serial.println();
}
float calculateDewPoint(float T, float RH)
{
float b = 243.12;
float a = 17.625;
float y1 = log(RH / 100.00); //-0.58
float y2 = (a * T) / (b + T); //
float dP = (b * (y1 + y2)) / (a - (y1 + y2));
return (dP);
}
Output:
Enter Temperature and Humidity as (TT.TT, HH.HH): 34.50, 56.75
Dew point: 24.67 degC
Enter Temperature and Humidity as (TT.TT, HH.HH): 45.89, 67.00
Dew point: 38.29 degC
Enter Temperature and Humidity as (TT.TT, HH.HH):
there's a simpler formula see Dew point - Wikipedia
Thanks Golam. Understand most of the formula except
what is the ln in the expression 243.12*{ln ?????
Thanks
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