diff --git a/examples/MQ-Board-Calibration/MQ-Board-Calibration.ino b/examples/MQ-Board-Calibration/MQ-Board-Calibration.ino
index 0f31b6d..1bb1e10 100644
--- a/examples/MQ-Board-Calibration/MQ-Board-Calibration.ino
+++ b/examples/MQ-Board-Calibration/MQ-Board-Calibration.ino
@@ -101,15 +101,17 @@ void setup() {
 }
 
 void loop() {
+  //Review in serial port the measures
+  bool printRawData = true;
   //Read the sensor
-  int lecture2 =  MQ2.calibrate();
-  int lecture3 =  MQ3.calibrate();
-  int lecture4 =  MQ4.calibrate();
-  int lecture5 =  MQ5.calibrate();
-  int lecture6 =  MQ6.calibrate();
-  int lecture7 =  MQ7.calibrate();
-  int lecture8 =  MQ8.calibrate();
-  int lecture9 =  MQ9.calibrate();
+  int lecture2 =  MQ2.calibrate(printRawData);
+  int lecture3 =  MQ3.calibrate(printRawData);
+  int lecture4 =  MQ4.calibrate(printRawData);
+  int lecture5 =  MQ5.calibrate(printRawData);
+  int lecture6 =  MQ6.calibrate(printRawData);
+  int lecture7 =  MQ7.calibrate(printRawData);
+  int lecture8 =  MQ8.calibrate(printRawData);
+  int lecture9 =  MQ9.calibrate(printRawData);
 
   
   //Print in serial monitor
diff --git a/src/MQUnifiedsensor.cpp b/src/MQUnifiedsensor.cpp
index 9c593d5..2cb45bb 100644
--- a/src/MQUnifiedsensor.cpp
+++ b/src/MQUnifiedsensor.cpp
@@ -179,10 +179,12 @@ int MQUnifiedsensor::calibrate(boolean print) {
   R0 = RS_air/_ratioInCleanAir; //Calculate R0 
   if(print)
   {
+    Serial.println("*******Calibrating*********");
     Serial.println("_sensor_volt: " + String(_sensor_volt));
     Serial.println("_VOLT_RESOLUTION: " + String(_VOLT_RESOLUTION));
     Serial.println("_ratioInCleanAir: " + String(_ratioInCleanAir));
     Serial.println("R0: " + String(R0));
+    Serial.println("*******Calibrating*********");
   }
   return R0;
 }