diff --git a/BaseMQ.cpp b/BaseMQ.cpp
index c1daa38..3ac2fad 100644
--- a/BaseMQ.cpp
+++ b/BaseMQ.cpp
@@ -66,6 +66,11 @@ float BaseMQ::readRs() {
   return rs;
 }
 
+int readScaled(float a, float b) {
+  float ratio = readRs()/_ro;
+  return pow(M_E, (log(ratio)-b)/a);
+}
+
 float BaseMQ::getRo() {
   return _ro;
 }
diff --git a/BaseMQ.h b/BaseMQ.h
index 6aaf1bc..d830d80 100644
--- a/BaseMQ.h
+++ b/BaseMQ.h
@@ -31,9 +31,10 @@ protected:
 	uint8_t _pin;
 	uint8_t _pinHeater;
 	float readRs();
+	int readScaled(float a, float b);
 	float calculateResistance(int rawAdc);
 	virtual float getRoInCleanAir() const = 0;
 	virtual int getRL() const = 0;
 };
 
-#endif 
\ No newline at end of file
+#endif 
diff --git a/MQ2.cpp b/MQ2.cpp
index 6c0a29d..0b897de 100644
--- a/MQ2.cpp
+++ b/MQ2.cpp
@@ -9,22 +9,17 @@ MQ2::MQ2(uint8_t pin, uint8_t pinHeater)
 }
 
 unsigned long MQ2::readLPG() {
-  return readPpm(-0.45, 2.95);
+  return readScaled(-0.45, 2.95);
 }
 
 unsigned long MQ2::readMethane() {
-  return readPpm(-0.38, 3.21);
+  return readScaled(-0.38, 3.21);
 }
 
 unsigned long MQ2::readSmoke() {
-  return readPpm(-0.42, 3.54);
+  return readScaled(-0.42, 3.54);
 }
 
 unsigned long MQ2::readHydrogen() {
-  return readPpm(-0.48, 3.32);
-}
-
-int MQ2::readPpm(float a, float b) {
-  float ratio = readRs()/_ro;
-  return pow(M_E, (log(ratio)-b)/a);
+  return readScaled(-0.48, 3.32);
 }
diff --git a/MQ2.h b/MQ2.h
index a563c10..6f1e2bb 100644
--- a/MQ2.h
+++ b/MQ2.h
@@ -12,11 +12,10 @@ public:
 	unsigned long readSmoke();
 	unsigned long readHydrogen();
 private:
-	int readPpm(float a, float b);
 	// Резистор установленный на плату (кОм)
 	virtual int getRL() const { return 5; }
 	// коефициент чистого воздуха
 	virtual float getRoInCleanAir() const { return 9.83; }
 };
 
-#endif  // MQ2_H_
\ No newline at end of file
+#endif  // MQ2_H_
diff --git a/MQ3.cpp b/MQ3.cpp
index 2d4e321..71053b0 100644
--- a/MQ3.cpp
+++ b/MQ3.cpp
@@ -9,14 +9,9 @@ MQ3::MQ3(uint8_t pin, uint8_t pinHeater)
 }
 
 float MQ3::readAlcoholMgL() {
-  return readMgL(-0.66, -0.62);
+  return readScaled(-0.66, -0.62);
 }
 
 float MQ3::readAlcoholPpm() {
-  return readMgL(-0.66, -0.62)*2.2;
-}
-
-float MQ3::readMgL(float a, float b) {
-  float ratio = readRs()/_ro;
-  return pow(M_E, (log(ratio)-b)/a);
+  return readScaled(-0.66, -0.62)*2.2;
 }
diff --git a/MQ3.h b/MQ3.h
index e796480..7bfc1fc 100644
--- a/MQ3.h
+++ b/MQ3.h
@@ -10,11 +10,10 @@ public:
 	float readAlcoholMgL();
 	float readAlcoholPpm();
 private:
-	float readMgL(float a, float b);
 	// Резистор установленный на плату (кОм)
 	virtual int getRL() const { return 200; }
 	// коефициент чистого воздуха
 	virtual float getRoInCleanAir() const { return 60; }
 };
 
-#endif  // MQ3_H_
\ No newline at end of file
+#endif  // MQ3_H_
diff --git a/MQ4.cpp b/MQ4.cpp
index f377862..c63496e 100644
--- a/MQ4.cpp
+++ b/MQ4.cpp
@@ -9,10 +9,5 @@ MQ4::MQ4(uint8_t pin, uint8_t pinHeater)
 }
 
 unsigned long MQ4::readMethane() {
-  return readPpm(-0.36, 2.54);
-}
-
-int MQ4::readPpm(float a, float b) {
-  float ratio = readRs()/_ro;
-  return pow(M_E, (log(ratio)-b)/a);
+  return readScaled(-0.36, 2.54);
 }
diff --git a/MQ4.h b/MQ4.h
index a8b1f38..1555fd2 100644
--- a/MQ4.h
+++ b/MQ4.h
@@ -9,11 +9,10 @@ public:
 	MQ4(uint8_t pin, uint8_t pinHeater);
 	unsigned long readMethane();
 private:
-	int readPpm(float a, float b);
 	// Резистор установленный на плату (кОм)
 	virtual int getRL() const { return 20; }
 	// коефициент чистого воздуха
 	virtual float getRoInCleanAir() const { return 4.4; }
 };
 
-#endif  // MQ4_H_
\ No newline at end of file
+#endif  // MQ4_H_
diff --git a/MQ5.cpp b/MQ5.cpp
index a462094..2ab0b1e 100644
--- a/MQ5.cpp
+++ b/MQ5.cpp
@@ -9,14 +9,9 @@ MQ5::MQ5(uint8_t pin, uint8_t pinHeater)
 }
 
 unsigned long MQ5::readLPG() {
-  return readPpm(-0.39, 1.73);
+  return readScaled(-0.39, 1.73);
 }
 
 unsigned long MQ5::readMethane() {
-  return readPpm(-0.38, 1.97);
-}
-
-int MQ5::readPpm(float a, float b) {
-  float ratio = readRs()/_ro;
-  return pow(M_E, (log(ratio)-b)/a);
+  return readScaled(-0.38, 1.97);
 }
diff --git a/MQ5.h b/MQ5.h
index a2e3eda..30accb8 100644
--- a/MQ5.h
+++ b/MQ5.h
@@ -10,11 +10,10 @@ public:
 	unsigned long readLPG();
 	unsigned long readMethane();
 private:
-	int readPpm(float a, float b);
 	// Резистор установленный на плату (кОм)
 	virtual int getRL() const { return 20; }
 	// коефициент чистого воздуха
 	virtual float getRoInCleanAir() const { return 6.5; }
 };
 
-#endif  // MQ5_H_
\ No newline at end of file
+#endif  // MQ5_H_
diff --git a/MQ6.cpp b/MQ6.cpp
index 05843fc..d60cb26 100644
--- a/MQ6.cpp
+++ b/MQ6.cpp
@@ -9,10 +9,5 @@ MQ6::MQ6(uint8_t pin, uint8_t pinHeater)
 }
 
 unsigned long MQ6::readLPG() {
-  return readPpm(-0.42, 2.91);
-}
-
-int MQ6::readPpm(float a, float b) {
-  float ratio = readRs()/_ro;
-  return pow(M_E, (log(ratio)-b)/a);
+  return readScaled(-0.42, 2.91);
 }
diff --git a/MQ6.h b/MQ6.h
index c474480..fb14bc6 100644
--- a/MQ6.h
+++ b/MQ6.h
@@ -9,11 +9,10 @@ public:
 	MQ6(uint8_t pin, uint8_t pinHeater);
 	unsigned long readLPG();
 private:
-	int readPpm(float a, float b);
 	// Резистор установленный на плату (кОм)
 	virtual int getRL() const { return 20; }
 	// коефициент чистого воздуха
 	virtual float getRoInCleanAir() const { return 10; }
 };
 
-#endif  // MQ6_H_
\ No newline at end of file
+#endif  // MQ6_H_
diff --git a/MQ7.cpp b/MQ7.cpp
index dcb8563..abbc023 100644
--- a/MQ7.cpp
+++ b/MQ7.cpp
@@ -9,10 +9,5 @@ MQ7::MQ7(uint8_t pin, uint8_t pinHeater)
 }
 
 unsigned long MQ7::readCarbonMonoxide() {
-  return readPpm(-0.77, 3.38);
-}
-
-int MQ7::readPpm(float a, float b) {
-  float ratio = readRs()/_ro;
-  return pow(M_E, (log(ratio)-b)/a);
+  return readScaled(-0.77, 3.38);
 }
diff --git a/MQ7.h b/MQ7.h
index be281eb..cbda104 100644
--- a/MQ7.h
+++ b/MQ7.h
@@ -9,11 +9,10 @@ public:
 	MQ7(uint8_t pin, uint8_t pinHeater);
 	unsigned long readCarbonMonoxide();
 private:
-	int readPpm(float a, float b);
 	// Резистор установленный на плату (кОм)
 	virtual int getRL() const { return 10; }
 	// коефициент чистого воздуха
 	virtual float getRoInCleanAir() const { return 27; }
 };
 
-#endif  // MQ7_H_
\ No newline at end of file
+#endif  // MQ7_H_
diff --git a/MQ8.cpp b/MQ8.cpp
index c2897d1..762e032 100644
--- a/MQ8.cpp
+++ b/MQ8.cpp
@@ -9,10 +9,5 @@ MQ8::MQ8(uint8_t pin, uint8_t pinHeater)
 }
 
 unsigned long MQ8::readHydrogen() {
-  return readPpm(-1.52, 10.49);
-}
-
-int MQ8::readPpm(float a, float b) {
-  float ratio = readRs()/_ro;
-  return pow(M_E, (log(ratio)-b)/a);
+  return readScaled(-1.52, 10.49);
 }
diff --git a/MQ8.h b/MQ8.h
index ceb18ea..fae336c 100644
--- a/MQ8.h
+++ b/MQ8.h
@@ -9,11 +9,10 @@ public:
 	MQ8(uint8_t pin, uint8_t pinHeater);
 	unsigned long readHydrogen();
 private:
-	int readPpm(float a, float b);
 	// Резистор установленный на плату (кОм)
 	virtual int getRL() const { return 10; }
 	// коефициент чистого воздуха
 	virtual float getRoInCleanAir() const { return 70; }
 };
 
-#endif  // MQ8_H_
\ No newline at end of file
+#endif  // MQ8_H_
diff --git a/MQ9.cpp b/MQ9.cpp
index 95dd875..efc80ca 100644
--- a/MQ9.cpp
+++ b/MQ9.cpp
@@ -9,18 +9,13 @@ MQ9::MQ9(uint8_t pin, uint8_t pinHeater)
 }
 
 unsigned long MQ9::readLPG() {
-  return readPpm(-0.48, 3.33);
+  return readScaled(-0.48, 3.33);
 }
 
 unsigned long MQ9::readMethane() {
-  return readPpm(-0.38, 3.21);
+  return readScaled(-0.38, 3.21);
 }
 
 unsigned long MQ9::readCarbonMonoxide() {
-  return readPpm(-0.48, 3.10);
-}
-
-int MQ9::readPpm(float a, float b) {
-  float ratio = readRs()/_ro;
-  return pow(M_E, (log(ratio)-b)/a);
+  return readScaled(-0.48, 3.10);
 }
diff --git a/MQ9.h b/MQ9.h
index 4a4b28f..b375598 100644
--- a/MQ9.h
+++ b/MQ9.h
@@ -11,11 +11,10 @@ public:
 	unsigned long readMethane();
 	unsigned long readCarbonMonoxide();
 private:
-	int readPpm(float a, float b);
 	// Резистор установленный на плату (кОм)
 	virtual int getRL() const { return 10; }
 	// коефициент чистого воздуха
 	virtual float getRoInCleanAir() const { return 9.8; }
 };
 
-#endif  // MQ9_H_
\ No newline at end of file
+#endif  // MQ9_H_