Sensitive material MQ-9 gas sensor is used to clean the air in the lower conductivity of tin dioxide (SnO2). Detection method using low temperature cycling (1.5V heating ) to detect carbon monoxide, conductivity sensors with carbon monoxide in the air increased with increasing gas concentration , spurious adsorption at high temperatures (5.0V heating ) detection of combustible gases methane, propane and cryogenic cleaning gases. Simple circuit can be used to change the conductivity , concentration of the gas is converted to the corresponding output signal. MQ-9 high gas sensor for carbon monoxide, methane , liquefied petroleum gas sensitivity , the sensor can detect a variety of gases containing carbon monoxide and flammable , is a low-cost sensors for a variety of applications .
Input voltage : DC5V Power consumption ( current ): 150mA
DO output : TTL digital 0 and 1 ( 0.1 and 5V)
AO output :0.1-0 .3 V ( relative to pollution ) , the maximum concentration of a voltage of about 4V
Special note: After the sensor is powered , needs to warm up around 20S, measured data was stable , heat sensor is a normal phenomenon , because the internal heating wire , if hot is not normal .