diff --git a/src/MQUnifiedsensor.h b/src/MQUnifiedsensor.h
index 65f0602..d86300c 100644
--- a/src/MQUnifiedsensor.h
+++ b/src/MQUnifiedsensor.h
@@ -25,14 +25,14 @@
 /*****************************Globals***********************************************/
 //From the graph, we can see that the resistance ratio in fresh air is a constant:
 #define RatioMQ2CleanAir 9.83 //RS / R0 = 9.83 ppm 
-#define RatioMQ3CleanAir 60   //RS / R0 = 9.83 ppm 
+#define RatioMQ3CleanAir 60   //RS / R0 = 60 ppm 
 #define RatioMQ4CleanAir 4.4  //RS / R0 = 4.4 ppm 
 #define RatioMQ5CleanAir 6.5  //RS / R0 = 6.5 ppm 
 #define RatioMQ6CleanAir 10   //RS / R0 = 10 ppm 
-#define RatioMQ7CleanAir 11.6 //RS / R0 = 11.6 ppm  
+#define RatioMQ7CleanAir 27.5 //RS / R0 = 27.5 ppm  
 #define RatioMQ8CleanAir 70   //RS / R0 = 70 ppm   
 #define RatioMQ9CleanAir 9.6  //RS / R0 = 9.6 ppm    
-#define RatioMQ131CleanAir 11 //RS / R0 = 11 ppm
+#define RatioMQ131CleanAir 15 //RS / R0 = 15 ppm
 #define RatioMQ135CleanAir 3.6//RS / R0 = 3.6 ppm     
 #define RatioMQ303CleanAir 1  //RS / R0 = 1 ppm    
 #define RatioMQ309CleanAir 11 //RS / R0 = 11 ppm