The MQ-136 is a Hydrogen Sulfide detection sensor with a sensing range of 1 – 200ppm. The sensing element is SnO2, which has lower conductivity in clean air. When H₂S gas exists, the sensor’s conductivity gets higher along with the gas concentration rising. A simple circuit makes measuring this change in conductivity and turning it into data fairly straight-forward, but does require some calibration.

Hydrogen sulfide (also known as H2S, sewer gas, swamp gas, stink damp, and sour damp) is a colorless gas known for its pungent “rotten egg” odor at low concentrations. It is extremely flammable and highly toxic.

Users can convert the change of conductivity to correspond output signal of gas concentration through a simple circuit.

MQ136 gas sensor has high sensitivity to H2S gas, also can monitor organic vapor including sulfur well. It a kind of low-cost sensor for kinds of applications.

This is a simple-to-use hydrogen gas sensor module, comes with the MQ136 gas sensor and circuitry to offer plug and use feature. The sensor is used in gas leakage detecting equipments in home and industry applications.

MQ136 gas sensor has high sensitivity to Hydrogen sulfide, Low sensitivity for other combustible gas.

Features: –

• Comes with signal output indicator LED
• Dual signal output (analog output and TTL level output)
• TTL output valid signal is low (the output low power signal light is bright, can be connected with the microcontroller IO port)
• The analog voltage increases with the increase of concentration, the higher the concentration, the higher the voltage
• Sensitive to hydrogen sulfide gas
• Has a long life and reliable stability
• Fast response recovery characteristics
• With the installation hole to facilitate the installation of fixed
• The probe can be inserted into the design, convenient test.
• Operating Voltage: 5VDC
• Current comsumption: 150mA
• Comes with 4 header pins:
• VCC: 5VDC
• GND: Ground
• DO: TTL digital output
• AO: Analog voltage output
• After the module is powered, please allow around 20 seconds for the preheating of element in the sensor for stable reading for targeted gas. It will get warm (~50ºC) and that is normal, but it should be burning your hand
• Product Size (mm): 30(L) x 20 (W) x 28 (H)
• Weight : 14 g

MQ136 Hydrogen Sulfide Sensor Applications: –

• Gas leak monitoring device suitable for home or factory, suitable for liquefied gas, butane, propane, methane, alcohol, hydrogen, smoke and other monitoring devices.
• Applicable occasions: MCU learning, electronic competition, product development, graduation design.