Problemas de calibración con el DHT 11

Hola tengo un sketch con el dht11 y el lcd 16x2, no tengo muy claro si el valor de la humedad es correcto, pero el de temperatura estoy seguro que me esta marcando 4 o 6º de más.

¿Es posible que en el sketch este mal? hay forma de calibrarlo?

/* YourDuino.com Example Software Sketch
DHT11 Humidity and Temperature Sensor test
Displayed on I2C LCD Display
Credits: Rob Tillaart
http://arduino-info.wikispaces.com/PROJECT-Temp-Humidity-Display
terry@yourduino.com */

/-----( Import needed libraries )-----/
#include <dht11.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>

/-----( Declare objects )-----/
// set the LCD address to 0x27 for a 16 chars 2 line display
// Set the pins on the I2C chip used for LCD connections:
// addr, en,rw,rs,d4,d5,d6,d7,bl,blpol
LiquidCrystal_I2C lcd(0x27, 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE); // Set the LCD I2C address
dht11 DHT11;

/-----( Declare Constants, Pin Numbers )-----/
#define DHT11PIN 7

void setup() /----( SETUP: RUNS ONCE )----/
{
Serial.begin(9600); //(Remove all ‘Serial’ commands if not needed)
lcd.begin(16,2); // initialize the lcd for 20 chars 4 lines, turn on backlight
lcd.backlight();
// Print a message to the LCD.
//lcd.setCursor(0, 1);
lcd.print(“DHT11 Temp/Humid”);

}/–(end setup )—/

void loop() /----( LOOP: RUNS CONSTANTLY )----/
{

int chk = DHT11.read(DHT11PIN);

Serial.print("Read sensor: ");
switch (chk)
{
case 0: Serial.println(“OK”); break;
case -1: Serial.println(“Checksum error”); break;
case -2: Serial.println(“Time out error”); break;
default: Serial.println(“Unknown error”); break;
}
lcd.setCursor(0, 1);

lcd.print(“C=”);
lcd.print((float)DHT11.temperature, 0);
Serial.print("Temperature (oC): ");
Serial.println((float)DHT11.temperature, 2);

lcd.print(" F=");
lcd.print(Fahrenheit(DHT11.temperature), 0);
Serial.print("Temperature (oF): ");
Serial.println(Fahrenheit(DHT11.temperature), 2);

lcd.print(" H=");
lcd.print((float)DHT11.humidity, 0);
lcd.print("%");
Serial.print("Humidity (%): ");
Serial.println((float)DHT11.humidity, 2);

Serial.print("Temperature (K): ");
Serial.println(Kelvin(DHT11.temperature), 2);

Serial.print("Dew Point (oC): ");
Serial.println(dewPoint(DHT11.temperature, DHT11.humidity));

Serial.print("Dew PointFast (oC): ");
Serial.println(dewPointFast(DHT11.temperature, DHT11.humidity));

delay(2000);
}/* --(end main loop )-- */

/-----( Declare User-written Functions )-----/
//
//Celsius to Fahrenheit conversion
double Fahrenheit(double celsius)
{
return 1.8 * celsius + 32;
}

//Celsius to Kelvin conversion
double Kelvin(double celsius)
{
return celsius + 273.15;
}

// dewPoint function NOAA
// reference: http://wahiduddin.net/calc/density_algorithms.htm
double dewPoint(double celsius, double humidity)
{
double A0= 373.15/(273.15 + celsius);
double SUM = -7.90298 * (A0-1);
SUM += 5.02808 * log10(A0);
SUM += -1.3816e-7 * (pow(10, (11.344*(1-1/A0)))-1) ;
SUM += 8.1328e-3 * (pow(10,(-3.49149*(A0-1)))-1) ;
SUM += log10(1013.246);
double VP = pow(10, SUM-3) * humidity;
double T = log(VP/0.61078); // temp var
return (241.88 * T) / (17.558-T);
}

// delta max = 0.6544 wrt dewPoint()
// 5x faster than dewPoint()
// reference: http://en.wikipedia.org/wiki/Dew_point
double dewPointFast(double celsius, double humidity)
{
double a = 17.271;
double b = 237.7;
double temp = (a * celsius) / (b + celsius) + log(humidity/100);
double Td = (b * temp) / (a - temp);
return Td;
}

/* ( THE END ) */

Gracias por leerme.

siempre podrías modificar la librería del sensor y restarle 4 o 6 o los que creas al resultado del metodo temperature ,creo que se llama, para que te de el resultado que queires