How to Use SJH-100A Cubic 100% Methane Sensor: Examples, Pinouts, and Specs

The SJH-100A is a high-precision methane sensor manufactured by Cubic. It is designed to detect and measure the concentration of methane gas in the environment, providing accurate readings for safety and monitoring purposes. This sensor is widely used in industrial safety systems, environmental monitoring, and gas detection applications.

1. Power Supply: Connect the VCC pin to a 5V DC power supply and the GND pin to the ground.
2. Analog Output: Connect the AOUT pin to an analog input pin on your microcontroller (e.g., Arduino UNO) to read the methane concentration as an analog voltage.
3. Digital Output: Connect the DOUT pin to a digital input pin on your microcontroller to receive a high/low signal indicating the presence of methane.

• Calibration: Ensure the sensor is calibrated in a methane-free environment before use.
• Ventilation: Place the sensor in a well-ventilated area to avoid false readings due to stagnant air.
• Temperature and Humidity: Operate the sensor within the specified temperature and humidity ranges for accurate readings.
• Warm-Up Time: Allow the sensor to warm up for at least 2 minutes before taking measurements.

// SJH-100A Methane Sensor Example Code for Arduino UNO

const int analogPin = A0; // Analog input pin connected to AOUT
const int digitalPin = 2; // Digital input pin connected to DOUT

void setup() {
  Serial.begin(9600); // Initialize serial communication at 9600 bps
  pinMode(digitalPin, INPUT); // Set digital pin as input
}

void loop() {
  int analogValue = analogRead(analogPin); // Read the analog value
  int digitalValue = digitalRead(digitalPin); // Read the digital value

  // Convert the analog value to a voltage (0-5V)
  float voltage = analogValue * (5.0 / 1023.0);

  // Print the analog value and voltage to the serial monitor
  Serial.print("Analog Value: ");
  Serial.print(analogValue);
  Serial.print(" - Voltage: ");
  Serial.print(voltage);
  Serial.println("V");

  // Print the digital value to the serial monitor
  if (digitalValue == HIGH) {
    Serial.println("Methane Detected!");
  } else {
    Serial.println("No Methane Detected.");
  }

  delay(1000); // Wait for 1 second before the next reading
}

1. No Output Signal: Ensure the sensor is properly connected to the power supply and ground. Check for loose connections.
2. Inaccurate Readings: Calibrate the sensor in a methane-free environment. Ensure the sensor is within the specified operating temperature and humidity ranges.
3. Slow Response Time: Allow the sensor to warm up for at least 2 minutes before taking measurements.

• Check Connections: Verify all connections are secure and correct.
• Calibration: Perform regular calibration to maintain accuracy.
• Environmental Factors: Ensure the sensor is placed in a well-ventilated area and within the specified operating conditions.

By following this documentation, users can effectively integrate the SJH-100A Cubic 100% Methane Sensor into their projects, ensuring accurate and reliable methane detection.