MQ-9 MQ9 Carbon Monoxide, Coal, Liquefied, Combustible Gas Sensor

The MQ9 is a methane, carbon monoxide gas detection sensor. The sensor includes tin dioxide as its sensing element. The SnO2 (tin dioxide)has lower conductivity in pure air. When the air has carbon Monoxide, Coal, Liquefied, flammable gases, the conductivity of the sensor gets higher. A simple device makes measuring this change in conductivity and turning it into obvious data. However, the sensor requires some calibration.

Before using the module, one must have to calibrate this sensor. This sensor estimates the flammable gas concentration using a resistance ratio. This ratio includes Maximum sensor resistance in 1000ppm R0 and internal resistance Rs. In pure air, after preheating, you need to upload the calibration code and wait for fifteen minutes until R0 reaches a fixed value.

When the air has Carbon Monoxide, Coal, Liquefied, Combustible Gas Sensor, the resistance of the sensor decreases. Hence, the output from the Gas sensor varies when the concentration of gas increases. We can adjust the sensitivity by adjusting the potentiometer.

Features

Good sensitivity to CO/Combustible Gas
High sensitivity to Methane, Propane, and CO
Long life, stable and low cost
Simple drive circuit

Specifications

Operating Voltage is +5V
Heating consumption: 0.5-340mW
Adjustable Load resistance
Heater Resistance: 33Ω±5%
Minimum detecting Concentration: 200ppm
Maximum Detecting Concentration: 1000/10000/10000ppm