How to Use TGS-2602: Examples, Pinouts, and Specs

The TGS-2602, manufactured by FIGARO, is a compact and reliable gas sensor designed to detect a variety of gases, including methane, propane, and other combustible gases. It operates on the principle of resistive change when exposed to target gases, providing a simple yet effective method for gas detection. This sensor is widely used in safety systems, environmental monitoring, and air quality control applications.

• Indoor air quality monitoring
• Gas leak detection in residential and industrial settings
• Environmental monitoring systems
• Smart home safety devices
• HVAC systems for air quality control

The TGS-2602 is designed to provide high sensitivity to target gases while maintaining low power consumption. Below are the key technical details:

The TGS-2602 has a simple pin layout, as shown below:

Note: Pins H1 and H2 are used to power the internal heater, while pins A and B are used to measure the sensor's resistance.

1. Powering the Sensor:

   • Connect the heater terminals (H1 and H2) to a stable 5V DC power supply. Ensure the voltage does not exceed the specified range to avoid damaging the sensor.
   • Use a current-limiting resistor if necessary to control the power supplied to the heater.

2. Measuring Gas Concentration:

   • Connect the sensing terminals (A and B) to a voltage divider circuit. Typically, a load resistor (RL) is connected in series with the sensor to measure the voltage drop across it.
   • The sensor's resistance (Rs) changes in the presence of target gases. This change can be measured and correlated to gas concentration using a calibration curve provided in the sensor's datasheet.

3. Interfacing with a Microcontroller:

   • The output voltage from the voltage divider can be read using an analog input pin of a microcontroller, such as an Arduino UNO.
   • Use the analog-to-digital converter (ADC) of the microcontroller to process the sensor's output and calculate gas concentration.

• Preheating: Allow the sensor to preheat for at least 24 hours before initial use to stabilize its performance.
• Calibration: Perform calibration in a controlled environment to ensure accurate gas concentration readings.
• Environmental Factors: Avoid exposing the sensor to high humidity, condensation, or corrosive gases, as these can affect its performance.
• Placement: Install the sensor in a location where it can effectively detect target gases without interference from other environmental factors.

Below is an example code snippet for interfacing the TGS-2602 with an Arduino UNO:

// TGS-2602 Gas Sensor Example Code for Arduino UNO
// This code reads the sensor's output voltage and calculates the resistance (Rs).

const int sensorPin = A0; // Analog pin connected to the sensor's output
const float RL = 10.0;    // Load resistor value in kΩ

void setup() {
  Serial.begin(9600); // Initialize serial communication
  Serial.println("TGS-2602 Gas Sensor Test");
}

void loop() {
  int sensorValue = analogRead(sensorPin); // Read analog value (0-1023)
  float voltage = (sensorValue / 1023.0) * 5.0; // Convert to voltage (0-5V)
  
  // Calculate sensor resistance (Rs)
  float Rs = (5.0 - voltage) / (voltage / RL); 
  
  // Print the results
  Serial.print("Sensor Voltage: ");
  Serial.print(voltage);
  Serial.println(" V");
  
  Serial.print("Sensor Resistance (Rs): ");
  Serial.print(Rs);
  Serial.println(" kΩ");
  
  delay(1000); // Wait for 1 second before the next reading
}

Note: Replace the RL value in the code with the actual load resistor value used in your circuit.

1. No Output or Incorrect Readings:

   • Cause: Improper wiring or loose connections.
   • Solution: Double-check all connections and ensure the sensor is powered correctly.

2. Unstable Readings:

   • Cause: Insufficient preheating time or environmental interference.
   • Solution: Allow the sensor to preheat for at least 24 hours and ensure it is placed in a stable environment.

3. Sensor Not Responding to Gases:

   • Cause: Sensor may be damaged or exposed to extreme conditions.
   • Solution: Verify the operating conditions and replace the sensor if necessary.

4. High Power Consumption:

   • Cause: Incorrect heater voltage or excessive current draw.
   • Solution: Use a regulated power supply and ensure the heater voltage is within the specified range.

Q1: Can the TGS-2602 detect gases other than methane and propane?
Yes, the TGS-2602 can detect a variety of combustible gases. However, its sensitivity and accuracy may vary depending on the gas type.

Q2: How often should the sensor be calibrated?
Calibration frequency depends on the application and environmental conditions. For critical applications, periodic calibration is recommended.

Q3: Can the sensor be used outdoors?
The TGS-2602 is designed for indoor use. If used outdoors, ensure it is protected from moisture, dust, and extreme temperatures.

Q4: What is the expected lifespan of the TGS-2602?
The sensor typically has a lifespan of 5 years under normal operating conditions.