Electronics

MQ 2 Gas Detection Sensor Module

AED 19.00

1

Description

The MQ2 Smoke Sensor Module is commonly used in smoke detectors, gas leakage detectors, fire alarm systems, and industrial safety applications. It provides a cost-effective solution for gas detection and plays a crucial role in ensuring early detection of potentially hazardous situations. This gas sensor detects smoke, LPG, alcohol, hydrogen, methane, propane, and carbon monoxide in the air.

 

Package Includes:

  • 1x MQ2 Smoke Sensor Module

 

Features:

  • Gas Detection: The module is capable of detecting a wide range of gases, including smoke, LPG, propane, hydrogen, methane, alcohol, and more. It is particularly sensitive to combustible gases.
  • Sensitivity Adjustment: The sensitivity of the module can be adjusted using a potentiometer. This allows for customization and optimization of the detection threshold according to specific requirements.
  • Analog Output: The module provides an analog voltage output that corresponds to the concentration of the detected gas. This output can be easily interfaced with microcontrollers, ADCs (Analog-to-Digital Converters), or other digital devices for further processing and analysis.
  • Fast Response Time: The module exhibits a rapid response time when detecting gases, enabling quick detection and response to potential hazards.
  • Stable Performance: It offers stable and reliable performance over an extended period, making it suitable for long-term gas monitoring applications.
  • Low Power Consumption: The module operates on low power, making it energy-efficient and suitable for battery-powered devices.
  • Easy Integration: The MQ2 Smoke Sensor Module is compact and easy to integrate into various electronic systems and projects. It typically comes with mounting holes or pins for convenient installation.
  • Cost-Effective Solution: The module provides an affordable and cost-effective solution for gas detection needs, making it accessible for both hobbyist projects and commercial applications.

 

Description:

The MQ2 Smoke Sensor Module is a commonly used electronic component designed to detect the presence of smoke and other gases in the air. It operates on the principle of gas conductivity, where the resistance of its sensing element changes in the presence of specific gases. The module consists of a small circuit board with an MQ2 gas sensor at its center. The sensor includes a small heating element and a sensing element coated with a material that reacts to the target gases. When the module is powered on, the heating element heats up the sensing element, enabling it to detect gases. The MQ2 Smoke Sensor Module can detect various gases, including smoke, LPG, propane, hydrogen, methane, alcohol, and more. It is particularly sensitive to combustible gases and can trigger an alarm or activate other devices when gas concentrations exceed a predefined threshold. The module outputs an analog voltage signal that corresponds to the gas concentration level. This analog signal can be read by a microcontroller or other digital devices for further processing or triggering appropriate actions. This module has a pot (variable resistor) for adjusting the sensor's sensitivity. And it gets quite hot after a time, so don't touch it!

 

Principle of Work:

The MQ2 Smoke Sensor Module operates based on the principle of gas conductivity. It consists of an internal sensor component known as the MQ2 gas sensor, which is at the heart of its detection mechanism. The MQ2 sensor comprises a heating element and a sensing element. The heating element is responsible for heating the sensing element to a specific temperature range. This heating process is necessary to activate the sensor and make it sensitive to the target gases. The sensing element is made up of a material that undergoes changes in electrical conductivity when exposed to certain gases. It is typically a metal oxide semiconductor material that reacts to the presence of combustible gases like smoke, LPG, methane, and so on. When these gases come into contact with the sensing element, they cause a change in its electrical resistance. The module applies a constant voltage across the sensing element, and the resulting current passing through it is measured. When there is no target gas present, the sensing element exhibits a relatively high resistance, causing a low current flow. However, when the target gas is detected, the resistance of the sensing element decreases, allowing a higher current to flow through it. The change in current flow corresponds to the concentration of the detected gas. The module converts this current variation into an analog voltage signal, which can be read by a microcontroller or other digital devices. By monitoring the analog output, one can determine the presence and concentration of the target gas. The MQ2 sensor's response to different gases may vary, and it may have cross-sensitivity to some extent. Therefore, calibration and testing are often required to establish accurate detection thresholds and compensate for any potential interference from other gases. The sensitivity of the module can be adjusted using a potentiometer present on the module, allowing users to fine-tune the detection level according to their specific needs.

 

Pinout of the Module:

The MQ2 Smoke Sensor Module consists of the following onboard components:

  1. MQ2 Gas Sensor: This is the main sensing element responsible for detecting the target gases. It includes a heating element and a metal oxide semiconductor sensing element.
  2. Potentiometer: The module usually includes a potentiometer or trimmer potentiometer that allows you to adjust the sensitivity of the sensor. Turning the potentiometer clockwise or counterclockwise can increase or decrease the detection threshold, respectively.
  3. Power Indicator LED: Many modules have an onboard power indicator LED that lights up when the module is powered on.
  4. Analog Output: The module provides an analog output that represents the concentration of the detected gas. It is typically in the form of a pin or header that can be connected to a microcontroller or ADC for reading the analog voltage signal.

The MQ2 Smoke Sensor Module commonly has four pins:

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.

 

Applications:

  • Smoke Detectors: The module is widely used in smoke detectors to detect the presence of smoke, providing an early warning system in residential, commercial, and industrial buildings.
  • Gas Leakage Detectors: It is used in gas leakage detection systems to identify the presence of combustible gases like LPG, propane, methane, and others. This helps prevent gas leaks, ensuring safety in homes, kitchens, and industrial settings.
  • Fire Alarm Systems: The module is employed in fire alarm systems to detect the presence of smoke or combustion gases, triggering alarms and activating safety measures.
  • Industrial Safety: It plays a crucial role in industrial safety applications by detecting hazardous gases such as hydrogen, alcohol, and volatile organic compounds (VOCs), ensuring worker safety in environments where these gases may be present.
  • Environmental Monitoring: The module is utilized in environmental monitoring systems to measure air quality and detect the presence of harmful gases in indoor and outdoor environments.
  • Gas Detection in Vehicles: It is employed in automotive applications to detect gas leaks or the presence of hazardous gases in vehicles, ensuring passenger safety.
  • Gas Detection in Laboratories: The module is used in laboratories to monitor and detect the presence of gases in chemical reactions or experiments, providing a safe working environment.
  • IoT and Smart Home Applications: The module can be integrated into Internet of Things (IoT) devices and smart home systems for remote gas monitoring, alert notifications, and automation of safety measures.

 

Circuit:

 

 

To interface the MQ2 Gas Smoke Sensor with the Arduino UNO Connect the MQ2 Gas Smoke Sensor module to the Arduino UNO using the appropriate wiring. Refer to the module's datasheet or pinout diagram to determine the correct connections for VCC to 5v, GND to GND, DOUT to Pin 8, and AOUT pin to A0.

 

Library:

This Module doesn't need any Library to function.

Code:

  1. Launch the Arduino IDE and create a new sketch.
  2. Copy and paste the code provided for interfacing the MQ2 Gas Smoke Sensor into the Arduino IDE.
  3. Upload the code to the Arduino UNO board.
#define MQ2pin (0)

float sensorValue;  //variable to store sensor value

void setup()
{
  Serial.begin(9600); // sets the serial port to 9600
  Serial.println("Gas sensor warming up!");
  delay(20000); // allow the MQ-6 to warm up
}

void loop()
{
  sensorValue = analogRead(MQ2pin); // read analog input pin 0
  
  Serial.print("Sensor Value: ");
  Serial.print(sensorValue);
  
  if(sensorValue > 300)
  {
    Serial.print(" | Smoke detected!");
  }
  
  Serial.println("");
  delay(2000); // wait 2s for next reading
}
  1. Open the Serial Monitor in the Arduino IDE. Set the baud rate to match the one specified in the code.
  2. Now, take the MQ2 Gas Smoke Sensor module to an area with smoke or simulated smoke.
  3. Observe the readings on the Serial Monitor. You should see sudden variations in the readings as the sensor detects the presence of smoke or other gases.

The Serial Monitor displays the output from the Arduino UNO, which indicates the gas concentration or the presence of smoke as detected by the MQ2 sensor. By taking the device into a smokey environment, you can observe the changes in the readings reflected on the Serial Monitor in real time.

 

Technical Details:

Operating voltage 5V
Load resistance 20 KΩ
Heater resistance 33Ω ± 5%
Heating consumption <800mw
Sensing Resistance 10 KΩ – 60 KΩ
Concentration Scope 200 – 10000ppm
Preheat Time Over 24 hour

Resources:

 

Comparisons:

What are the key differences in terms of sensitivity, target gases, and applications between the MQ2 module and the MQ6 module? When comparing the MQ2 module to the MQ6 module, there are several key differences to consider:

  1. Target Gases: The MQ2 module is designed to detect a broad range of gases, including smoke, LPG, propane, hydrogen, methane, alcohol, and more. It has a wide sensitivity range and is sensitive to multiple gases. On the other hand, the MQ6 module is specifically optimized for detecting LPG (liquefied petroleum gas) and methane gases. It provides higher accuracy and sensitivity for these specific gases.
  2. Gas Differentiation: The MQ2 module may not be suitable for distinguishing between different types of gases. It provides a general indication of gas presence but does not differentiate between specific gases. In contrast, the MQ6 module is designed to detect LPG and methane gases specifically, allowing for more targeted gas differentiation.
  3. Module Functionality: Both modules consist of a sensor and a module for simplified integration. The MQ2 module includes an op-amp comparator and a digital output pin, making it suitable for detecting the presence of a gas. The MQ6 module, depending on the specific version, may provide similar functionality or may offer an analog output for measuring the gas concentration in parts per million (ppm). The choice between digital or analog output depends on the intended application and requirements.
  4. Application Specificity: The MQ2 module is commonly used in smoke detectors, gas leakage detectors, fire alarm systems, and general gas detection applications. It offers versatility for a range of gas detection needs. In contrast, the MQ6 module is more specialized and primarily used for LPG and methane detection, making it a preferred choice for gas leak detection in homes, kitchens, and industrial settings.