The MQ5 module is an advanced gas sensor designed to detect and locate gas leaks efficiently, making it invaluable for both residential and industrial applications. This highly sensitive module can identify a wide range of substances, including alcohol, H2, LPG, CH4, and more. With its rapid response time and exceptional sensitivity, it enables swift and accurate gas measurements to be taken, ensuring timely detection and response to potential hazards. Utilizing a Metal Oxide Semiconductor (MOS) type gas sensor, also known as a chemiresistor, the MQ5 module relies on the variation in resistance of its sensing material upon contact with the gas, making it a reliable and effective tool for gas detection and safety.

 

Package Includes:

• 1x MQ5 LPG Sensor Module

 

Features:

• Signal output indication: The module provides a clear indication of the output signal, making it easy to monitor and detect gas presence.
• Dual signal output: It offers both analog output and TTL level output, allowing for flexible connectivity with different systems.
• Low TTL output signal: The TTL output signal is low, enabling direct connection to microcontrollers when the signal is low.
• 0 ~ 5V analog output voltage: The module provides an analog output voltage that ranges from 0 to 5V. The voltage increases as the gas concentration rises, facilitating accurate measurements.
• Enhanced sensitivity to specific gases: The MQ5 module exhibits better sensitivity towards liquefied petroleum gas (LPG), natural gas, and city gas, enabling reliable detection of these substances.
• Long lifespan and reliable stability: The module is designed for long-term use, offering durability and consistent performance over time.
• Fast response and recovery characteristics: The MQ5 module quickly responds to changes in gas levels, ensuring rapid detection and enabling prompt action.
• Operating voltage: The module operates at a voltage of DC 5V, conforming to standard power supply requirements.
• Gas detection capabilities: The MQ5 sensor can detect LPG and CH4 gases within a range of 300 to approximately 10,000ppm. Additionally, it can be used to detect H2, CO, and alcohol, expanding its applicability to various gas detection scenarios.

 

Description:

The MQ5 module is a versatile gas sensor designed to detect and measure the presence of various gases in different environments. It is commonly used in both residential and industrial settings for gas leak detection and safety purposes. The module's primary function is to analyze the concentration of gases such as alcohol, H2, LPG, CH4, and other substances. The MQ5 module operates based on the principle of a Metal Oxide Semiconductor (MOS) gas sensor, also known as a Chemiresistor. It relies on the changes in resistance of its sensing material when it comes into contact with different gases. This variation in resistance enables the module to accurately detect and quantify the presence of specific gases. One of the advantages of the MQ5 module is its high sensitivity and fast response time. This allows for quick and efficient gas detection, ensuring timely awareness of any potential gas leaks. The module is designed to provide reliable and accurate measurements, providing users with the necessary information to take appropriate safety precautions. Furthermore, the MQ5 module is built to be user-friendly and easy to integrate into existing systems. It typically offers both analog and TTL level output signals, allowing for convenient connection to microcontrollers or other devices for data processing and analysis.

 

Principle of Work:

The MQ5 module operates based on the principle of a Metal Oxide Semiconductor (MOS) gas sensor, commonly known as a Chemiresistor. The internal build of the module sensor consists of a sensing element made of a metal oxide semiconductor material, typically tin dioxide (SnO2), along with a heating element and a protective mesh. When the MQ5 module is powered on, the heating element is activated, heating up the sensing element. This heating process enables the sensor to reach an optimal operating temperature for gas detection. As the target gas comes into contact with the heated sensing element, it undergoes a chemical reaction with the metal oxide semiconductor material. This reaction causes a change in the electrical conductivity of the sensing material, leading to a variation in resistance. The resistance change is then measured and converted into a corresponding electrical signal by the module's internal circuitry. This signal can be interpreted to determine the presence and concentration of the specific gas being detected.

The MQ5 module typically provides two types of output signals. The analog output signal represents the gas concentration as a voltage level, where a higher concentration results in a higher output voltage. This analog voltage can be further processed or utilized for monitoring and control purposes. Additionally, the module often includes a TTL (Transistor-Transistor Logic) level output signal. This output provides a digital indication of gas presence, with a low signal indicating the detection of gas and a high signal indicating its absence. By monitoring the changes in resistance and converting them into measurable electrical signals, the MQ5 module enables the detection and measurement of gases such as alcohol, H2, LPG, CH4, and other substances.

 

Pinout of the Module:

Pin Name	Description
VCC	supplies power for the module. You can connect it to 5V output from your Arduino.
GND	is the Ground Pin and needs to be connected to the GND pin on the Arduino.
D0	provides a digital representation of the presence of combustible gases.
A0	provides analog output voltage is proportional to the concentration of smoke/gas.

• The MQ5 LPG Sensor Module is equipped with four pins, with VCC and Gnd serving as the power and ground connections, respectively. The other two pins are capable of simultaneously providing analog and digital output data. The module operates within a working voltage range of 5V, with a tolerance of 0.1%. In our setup, we are utilizing the 5V port of the Arduino to power the circuit.
• Within the module, you will find two internal LEDs. The power LED illuminates when the board is powered up, indicating that it is receiving power. On the other hand, the doubt LED activates when the trigger value, set by the potentiometer, is reached, indicating the detection of a certain gas level.
• To convert the analog signal from the gas sensor into a digital signal, the module employs an integrated comparator OP-Amp. This conversion allows for easy processing and analysis of the gas sensor's input signal. Additionally, the module includes a Trim-pot that enables us to adjust the sensitivity of the device, providing flexibility in detecting gas concentrations.
• To ensure optimal performance, the module incorporates resistor capacitors for decoupling and filtering. These components help stabilize the electrical signals and minimize any noise or interference that may affect the module's operation.

 

Applications:

1. Gas leak detection in residential settings: The module can be used to detect gas leaks, such as LPG or natural gas, in homes and apartments, ensuring early detection and preventing potential hazards.
2. Industrial gas detection: The MQ5 module is employed in industrial environments to detect gases like methane (CH4), which is commonly found in manufacturing plants, refineries, and storage facilities. It helps ensure worker safety and enables timely response to gas leaks or spills.
3. Fire safety systems: The module's ability to detect flammable gases makes it suitable for integration into fire safety systems. It can trigger alarms or activate fire suppression mechanisms in the presence of combustible gases.
4. Gas detectors for vehicles: The MQ5 module can be utilized in gas detectors installed in vehicles, such as cars or recreational vehicles (RVs), to monitor gas leaks from fuel tanks or gas-powered appliances, providing an added layer of safety during transportation or camping trips.
5. Environmental monitoring: The module's sensitivity to gases like alcohol and carbon monoxide (CO) allows for its use in environmental monitoring systems. It can aid in detecting and measuring pollutants in the air, ensuring a healthier environment.
6. Laboratory and research applications: The MQ5 module finds utility in laboratory settings for gas analysis and research purposes. Its ability to detect a range of gases, including H2 and alcohol, enables scie

 

Circuit:

1. Connect the VCC of the module 5v and GNd to GND and the analog output pin of the MQ5 module to analog pin 0 (A0) on the Arduino.

   • MQ5pin -> A0

2. Connect the digital output pin of the MQ5 module to digital pin 8 on the Arduino.

   • MQ5 digital output pin -> Arduino digital pin 8

3. Connect an LED to digital pin 13 on the Arduino for visual indication.

   • Arduino digital pin 13 -> LED (+) terminal
   • Connect a resistor in series with the LED, and connect the other end of the resistor to GND (ground).

 

Library:

This Module doesn't need any Library to function.

 

Code:

In this Example code, the Serial Monitor will display the gas level read from the MQ5 sensor in "units." Additionally, it will provide a message indicating whether gas is detected above the threshold or if no gas is detected. The LED connected to digital pin 13 will also be turned on or off accordingly to visually indicate the presence of gas:

#define MQ5pin A0 // Analog input pin for MQ5 sensor
#define DigitalPin 8 // Digital input pin for MQ5 sensor
#define LedPin 13 // Digital output pin for LED indicator

float sensorValue; // Variable to store sensor value

void setup() {
  pinMode(LedPin, OUTPUT);
  Serial.begin(9600); // Sets the serial port baud rate to 9600
  Serial.println("MQ5 Gas Sensor warming up...");
  delay(20000); // Allow the MQ5 sensor to warm up
}

void loop() {
  sensorValue = analogRead(MQ5pin); // Read analog input from MQ5 sensor
  Serial.print("Gas Level: ");
  Serial.print(sensorValue);
  Serial.println(" units");

  if (digitalRead(DigitalPin)) {
    digitalWrite(LedPin, HIGH); // Turn on the LED indicator if gas is detected
    Serial.println("Gas detected above threshold!");
  } else {
    digitalWrite(LedPin, LOW); // Turn off the LED indicator if no gas is detected
    Serial.println("No gas detected.");
  }
  
  delay(2000); // Wait for 2 seconds before taking the next reading
}

 

 

1. The code begins by defining the necessary pins and variables:

   • MQ5pin is defined as the analog input pin (A0) connected to the MQ5 sensor.
   • DigitalPin is defined as the digital input pin (8) connected to the MQ5 sensor.
   • LedPin is defined as the digital output pin (13) connected to an LED indicator.

2. In the setup() function:

   • The LedPin is configured as an output pin using pinMode() to control the LED.
   • The serial communication is initialized with a baud rate of 9600 using Serial.begin().
   • A warming-up message is sent to the Serial Monitor using Serial.println().
   • The program waits for 20 seconds using delay() to allow the MQ5 sensor to warm up.

3. In the loop() function:

   • The analog value from the MQ5 sensor connected to MQ5pin is read using analogRead() and stored in the sensorValue variable.
   • The gas level value is printed to the Serial Monitor using Serial.print() and Serial.println().
   • The code checks the digital input from DigitalPin using digitalRead() to determine if the gas level is above the threshold.
   • If the gas level is above the threshold, the LED connected to LedPin is turned on using digitalWrite(), and a message is printed to the Serial Monitor.
   • If the gas level is below the threshold, the LED is turned off, and a corresponding message is printed.
   • The program then waits for 2 seconds using delay() before taking the next reading.

 

Technical Details:

• Item Weight: 10.0 grams
• Heater Voltage: 5.0V
• Power Supply: 5 Volts
• Interface Type: Analog & Digital
• Working Current: 150mA
• Digital Output (DOUT): TTL output
• Analog Output (AOUT): Analog output
• Preheat Time: Over 20 seconds
• Heater Resistance: 31±10%
• Adjustable Resistance
• Sensing Resistance Range: 10 – 60K
• Sensor Heat Consumption: 0.5-800mW
• Detecting Concentration Range: 200-10000ppm

 

Resources:

MQ-5.pdf 

 

Comparisons:

while the MQ5 and MQ2 sensor modules share similarities in terms of functionality and application, they have slight differences in the specific gases they can detect. The MQ2 module offers a broader range of target gases, including smoke detection, while the MQ5 module focuses more on LPG, CH4, and combustible gases. Both modules provide analog and digital output signals and find utility in gas detection and safety monitoring systems, Here is a comparison between the MQ5 and MQ2 Gas Sensor modules:

1. Target Gases:

   • MQ5: The MQ5 sensor module is primarily designed for detecting gases such as LPG, CH4 (methane), alcohol, hydrogen, and other combustible gases.
   • MQ2: The MQ2 sensor module is capable of detecting gases such as LPG, propane, methane, alcohol, hydrogen, smoke, and various other combustible and flammable gases.

2. Sensitivity:

   • MQ5: The MQ5 module exhibits high sensitivity to LPG, CH4, and other combustible gases.
   • MQ2: The MQ2 module also offers high sensitivity to a range of combustible and flammable gases.

3. Output Signals:

   • MQ5: The MQ5 module provides both analog and digital (TTL) output signals, allowing for compatibility with microcontrollers and other digital systems.
   • MQ2: Similar to the MQ5, the MQ2 module offers both analog and digital (TTL) output signals.

4. Applications:

   • MQ5: The MQ5 module is commonly used for gas leak detection, industrial safety monitoring, domestic gas leakage detection, and other applications where the detection of combustible gases is crucial.
   • MQ2: The MQ2 module is widely employed in gas leak detection systems, fire detection systems, gas concentration measurement, and various safety monitoring applications.

5. Sensing Range:

   • MQ5: The MQ5 sensor can detect LPG and CH4 gases in the range of approximately 300 to 10,000 parts per million (ppm).
   • MQ2: The MQ2 sensor has a detecting concentration range of 200 to 10,000 ppm for various combustible gases.