Sensor MQ-7 Description: MQ-7 gas sensor is sensitive material used in clean air, low conductivity tin dioxide (SnO2). Detection method using low temperature cycling (1.5V heating) detect carbon monoxide, airborne sensor conductivity increases with the increase of the concentration of carbon monoxide gas, high temperature (5.0V heating) cleaning stray gas adsorption at low temperature. Using a simple circuit can be changes in the conductivity, concentration of the gas is converted to the corresponding output signal. MQ-7 gas sensor with high sensitivity for carbon monoxide, this sensor can detect a variety of gases containing carbon monoxide, is a low-cost sensors for a variety of applications,
Module Applications: For home, carbon monoxide detection device environment. Suitable for carbon monoxide and gas detection. Module Features: 1, using high-quality dual-panel design, with power indicator and TTL signal output instructions; 2, with a DO switch signal (TTL) output and AO analog signal output; 3, TTL output valid signal is low. (When the output low signal light can be directly connected microcontroller or relay module) 4, the analog output voltage, the higher the concentration the higher the voltage. 5, the carbon monoxide detection with better sensitivity. 6, there are four screw holes for easy positioning; 7, Product Dimensions: 32 (L) * 20 (W) * 22 (H) 8, with a long service life and reliable stability 9, rapid response and recovery characteristics
Electrical properties: Input voltage: DC5V power (current): 150mA DO output: TTL digital 0 and 1 (0.1 and 5V) AO output :0.1-0 .3 V (relatively clean), the highest concentration of voltage around 4V Special note: The sensor is powered, needs to warm up around 20S, measured data becomes stable, the sensor fever is a normal phenomenon, because the internal heating wire, if hot is not normal.