diff --git a/MQ135.cpp b/MQ135.cpp
index d565072..b0814d1 100755
--- a/MQ135.cpp
+++ b/MQ135.cpp
@@ -50,7 +50,12 @@ MQ135::MQ135(uint8_t pin, float rload, float rzero, float atmoco2, float vref, f
 */
 /**************************************************************************/
 float MQ135::getCorrectionFactor(float t, float h) {
-  return CORA * t * t - CORB * t + CORC - (h-33.)*CORD;
+  //return CORA * t * t - CORB * t + CORC - (h-33.)*CORD;
+
+  // This formula is reduced from temperature and humidity dependency graph,
+  // found in this datasheet:
+  // http://china-total.com/Product/meter/gas-sensor/MQ135.pdf
+  return (1.30732 - 0.0116044 * t) * (2.20591 - 0.296456 * log(h));
 }
 
 /**************************************************************************/
diff --git a/MQ135.h b/MQ135.h
index a18beec..50a1315 100755
--- a/MQ135.h
+++ b/MQ135.h
@@ -31,11 +31,13 @@ v1.0 - First release
 #define PARA 117.185
 #define PARB 2.65797
 
+/*
 /// Parameters to model temperature and humidity dependence
 #define CORA 0.00035
 #define CORB 0.02718
 #define CORC 1.39538
 #define CORD 0.0018
+*/
 
 /// Atmospheric CO2 level for calibration purposes, in PPM.
 /// See http://co2now.org/