MQ137 Ammonia NH3 Gas Sensor

The MQ137 Ammonia NH3 Gas Sensor is designed for NH3 gas detection, suitable for applications such as NH3 gas alarms, industrial NH3 gas leakage alarms, and portable NH3 gas detectors. Here are its key features and specifications:

  Features:  

• Sensitive Material: Uses SnO2, which has lower conductivity in clean air. The conductivity increases with rising NH3 gas concentration.
• Gas Detection: High sensitivity to NH3 gas, can also detect organic amines such as trimethylamine effectively.
• Operation Modes: Can be used as both digital and analog sensors.
• Voltage Range: Operates in an analog voltage range of 0V to 5V. For digital voltages, the output is either 0V or 5V.
• Stability: Provides stable operation with a fast response time.
• Adjustable Sensitivity: Sensitivity can be adjusted using a potentiometer to vary resistance.
• Preheating Duration: Features a preheating duration of over 24 hours.

  Specifications:  

• • Model: MQ137
  • Sensor Type: Semiconductor
  • Encapsulation: Bakelite, Metal cap
  • Target Gas: Ammonia Gas (NH3)
  • Detection Range: 5 to 500 ppm NH3
  • Loop Voltage (Vc): 24V DC
  • Heater Voltage (VH): 5.0V ± 0.1V AC or DC
  • Load Resistance (RL): Adjustable
  • Heater Resistance (RH): 29Ω ± 3Ω (room temp.)
  • Heater Consumption (PH): 900mW
  • Sensitivity (S): Rs(in air)/Rs(50ppmNH3) ≥ 2
  • Output Voltage (Vs): ≥ 0.5V (in 50ppm NH3)
  • Concentration Slope (α): 0.6 (R200ppm/R50ppm NH3)
  • Standard Test Conditions: 20°C ± 2°C; 55% ± 5% RH
    

  Standard Test Circuit:  

• • Temperature & Humidity: 20°C ± 2°C; 55% ± 5% RH
  • Vc: 5.0V ± 0.1V; VH: 5.0V ± 0.1V
  • Preheat Time: Over 48 hours
    

  Package Includes:  

• 1 x MQ137 Ammonia NH3 Gas Sensor

This sensor is suitable for applications requiring the detection of NH3 gas and organic amines, offering a stable operation and fast response time.