MQ-137 Ammonia Gas NH3 Sensor Module

MQ-137 Ammonia Gas NH3 Sensor Module can be used to monitor the concentration Ammonia gas (NH3).The gas-sensitive material used in the MQ137 gas sensor is tin dioxide (SnO2), which has low conductivity in clean air. When ammonia is present in the environment, the conductivity of the sensor increases as the ammonia concentration in the air increases. A simple circuit can be used to convert the change in conductivity into an output signal corresponding to the concentration of the gas.

MQ137 gas sensor has high sensitivity to ammonia, and it is also ideal for monitoring other organic amines (such as trimethylamine, ethanolamine, etc.). This sensor can detect a variety of ammonia-containing gases and is a low cost sensor suitable for many applications.

Features:

• Wide detecting scope
• Fast response (less than 1s)
• High sensitivity( 3%)
• the circuit voltage: DC5V
• Stable and long life
• Analog output voltage: 0V to 5V
• Digital output voltage: 0V or 5V (TTL Logic)
• Can be used as a digital or analog sensor
• The sensitivity of digital output can be adjusted using an onboard potentiometer
• The TTL output valid signal is low. (When the output is low, the signal light is on, it can be directly connected to the MCU or relay module)
• The voltage of the analog output, the higher the concentration, the higher the voltage.
• Arduino compatible

Specifications:

Operating Voltage (VDC)	5
Detect/Measure	NH3, Ammonia
Concentration	5-500ppm (Ammonia)
Heater Resistance (RH)	31Ω±3Ω Room Temp.
Heater Consumption (PH)	≤900mW
Sensing Resistance (Rs)	2KΩ-15KΩ (in 50ppm NH3)
Sensitivity(S)	Rs (in air)/Rs (5000ppm CH4) ≥ 5
Slope(α)	≤0.6(R100ppm/R50ppm NH3)
Output Voltage(V)	0 ~ 5
Length (mm)	35
Width (mm)	20
Height (mm)	28
Weight (gm)	10

Applications of MQ137 Gas Sensor

• Detector measure Gases like NH3 or CO
• Air quality monitor
• Gas leak alarm
• Safety standard maintenance
• Maintaining environmental standards  in hospitals
• How to detect gases with the MQ-137 gas sensor module?
• Power the gas sensor module with 5V and you should notice the power LED on the module glow.
• When no gas is detected the output LED will remain turned off meaning the digital output pin will be 0V.
• These sensors need pre-heating time before they can actually be used.
• Introduce the sensor to the gas you want to detect and you should see the output LED go high along with the digital pin, if not use the potentiometer until the output gets high.

Package Includes:

• 1 x MQ-137 Ammonia Gas NH3 Sensor Module